[Feat.] Add new feature DDM

[muneeb-jan]

What this PR does / why we need it

Adding DDM to GopherTelekomCloud.

DDM is the Distributed Database Middleware service of OTC.

Tests performed

V1 Tests

=== RUN   TestDDMQueryInstances
--- PASS: TestDDMQueryInstances (0.60s)
=== RUN   TestDDMInstancesLifecycle
    helper.go:108: Creating DDM Instance: ddm-instance-5Pr
    helper.go:123: Created DDM Instance: ddm-instance-5Pr
        DDM instance ID: 88a5e071c9f14a8d8869c3d8e9c5629din09
    instances_test.go:42: Renaming DDM Instance '88a5e071c9f14a8d8869c3d8e9c5629din09' to 'ddm-instance-renamed-lE4'
    instances_test.go:46: Renamed DDM Instance '88a5e071c9f14a8d8869c3d8e9c5629din09' to 'ddm-instance-renamed-lE4'
    helper.go:128: Attempting to delete DDM Instance with ID: 88a5e071c9f14a8d8869c3d8e9c5629din09
    helper.go:138: Deleted DDM Instance with ID: 88a5e071c9f14a8d8869c3d8e9c5629din09
--- PASS: TestDDMInstancesLifecycle (380.79s)
=== RUN   TestDDMSchemasLifecycle
    helper.go:108: Creating DDM Instance: ddm-instance-PL4
    helper.go:124: Created DDM Instance: ddm-instance-PL4
        DDM instance ID: 320cab8d53f84ce9a006b8cca1ec1ed9in09
    helper.go:18: Attempting to create RDSv3
    helper.go:65: Created RDSv3: 9426301bf3de4261b600daf4333f1800in01
    schemas_test.go:63: Creating DDM Schema: ddm_schema_acc_test_1
    schemas_test.go:72: Schema status: RUNNING
    schemas_test.go:80: Created DDM Schema: ddm_schema_acc_test_1
    schemas_test.go:83: Listing DDM Schemas: ddm_schema_acc_test_1
    schemas_test.go:88: DDM Schemas:
         []schemas.GetDatabaseInfo{schemas.GetDatabaseInfo{Name:"ddm_schema_acc_test_1", ShardMode:"cluster", ShardNumber:8, Status:"RUNNING", Created:1729198272422, UsedRds:[]schemas.GetDatabasesUsedRds{schemas.GetDatabasesUsedRds{ID:"9426301bf3de4261b600daf4333f1800in01", Name:"rds-test-iDR6fXGi", Status:"normal", ErrorMsg:""}}, ShardUnit:8}}
    schemas_test.go:91: Deleting DDM Schema: ddm_schema_acc_test_1
    schemas_test.go:100: Deleted DDM Schema: ddm_schema_acc_test_1
    helper.go:71: Attempting to delete RDSv3: 9426301bf3de4261b600daf4333f1800in01
    helper.go:82: RDSv3 instance deleted: 9426301bf3de4261b600daf4333f1800in01
    helper.go:129: Attempting to delete DDM Instance with ID: 320cab8d53f84ce9a006b8cca1ec1ed9in09
    helper.go:139: Deleted DDM Instance with ID: 320cab8d53f84ce9a006b8cca1ec1ed9in09
--- PASS: TestDDMSchemasLifecycle (800.25s)
=== RUN   TestDDMQueryAvailableDbInstances
    helper.go:108: Creating DDM Instance: ddm-instance-pYM
    helper.go:124: Created DDM Instance: ddm-instance-pYM
        DDM instance ID: 33ed6113957e4eeba4b5364c8ee1ada9in09
    helper.go:129: Attempting to delete DDM Instance with ID: 33ed6113957e4eeba4b5364c8ee1ada9in09
    helper.go:139: Deleted DDM Instance with ID: 33ed6113957e4eeba4b5364c8ee1ada9in09
--- PASS: TestDDMQueryAvailableDbInstances (375.69s)
PASS

V2 Tests

== RUN   TestQueryEngineInfoAndNodeClasses
--- PASS: TestQueryEngineInfoAndNodeClasses (6.90s)
=== RUN   TestDDMInstancesV2Scaling
    helper.go:108: Creating DDM Instance: ddm-instance-eZP
    helper.go:124: Created DDM Instance: ddm-instance-eZP
        DDM instance ID: ce1776b75d1b4b77aa75354092093f8din09
    instances_test.go:42: Scaling out DDM Instance ce1776b75d1b4b77aa75354092093f8din09
    instances_test.go:51: Scaled out DDM Instance ce1776b75d1b4b77aa75354092093f8din09 to n+1 nodes
    instances_test.go:54: Scaling in DDM Instance ce1776b75d1b4b77aa75354092093f8din09
    instances_test.go:62: Scaled in DDM Instance ce1776b75d1b4b77aa75354092093f8din09 to n-1 nodes
    helper.go:129: Attempting to delete DDM Instance with ID: ce1776b75d1b4b77aa75354092093f8din09
    helper.go:139: Deleted DDM Instance with ID: ce1776b75d1b4b77aa75354092093f8din09
--- PASS: TestDDMInstancesV2Scaling (838.42s)
=== RUN   TestDDMInstancesV2ModifyReadPolicy
--- PASS: TestDDMInstancesV2ModifyReadPolicy (1.93s)
PASS

V3 Tests

=== RUN   TestDDMInstancesTestV3
    helper.go:108: Creating DDM Instance: ddm-instance-6qS
    helper.go:124: Created DDM Instance: ddm-instance-6qS
        DDM instance ID: a0638acecef44bcc93f8d6a759ed7786in09
    instances_test.go:27: Listing parameters for DDM instance  a0638acecef44bcc93f8d6a759ed7786in09
    instances_test.go:32: Modifying parameters for DDM instance  a0638acecef44bcc93f8d6a759ed7786in09
    instances_test.go:42: Modifying node class for DDM instance  a0638acecef44bcc93f8d6a759ed7786in09
    instances_test.go:50: Modified node class for DDM instance  a0638acecef44bcc93f8d6a759ed7786in09
    helper.go:129: Attempting to delete DDM Instance with ID: a0638acecef44bcc93f8d6a759ed7786in09
    helper.go:139: Deleted DDM Instance with ID: a0638acecef44bcc93f8d6a759ed7786in09
--- PASS: TestDDMInstancesTestV3 (1059.08s)
=== RUN   TestDDMAccountsTestV3
    helper.go:108: Creating DDM Instance: ddm-instance-odR
    helper.go:124: Created DDM Instance: ddm-instance-odR
        DDM instance ID: 8437cf658516470db6cb04557d993775in09
    accounts_test.go:27: Resetting account password for DDM instance: 8437cf658516470db6cb04557d993775in09
    helper.go:129: Attempting to delete DDM Instance with ID: 8437cf658516470db6cb04557d993775in09
    helper.go:139: Deleted DDM Instance with ID: 8437cf658516470db6cb04557d993775in09
--- PASS: TestDDMAccountsTestV3 (387.44s)
PASS