return valid results when several status codes

[AlvaroVega]

When iotaRedirector retrieves several status codes from iotagents linke [200,200,400] then iotagentManager is responding with 400 error.

This PR tries to return the valid results retrieved by iotagent-manager instead just one error.

Related issue #167

• Tested with https://github.com/telefonicaid/fiware-IoTAgent-Cplusplus and a subservice with several '/'

This PR overcomes #249

[coveralls]

Pull Request Test Coverage Report for Build 1261150107

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 10 of 23 (43.48%) changed or added relevant lines in 1 file are covered.
• 14 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-1.3%) to 75.866%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/services/iotaRedirector.js	10	23	43.48%

Files with Coverage Reduction	New Missed Lines	%
lib/services/iotaRedirector.js	14	74.93%

Totals
Change from base Build 949284276:	-1.3%
Covered Lines:	506
Relevant Lines:	632

---

💛 - Coveralls

[AlvaroVega]

• Tested with a bad configured iotagent (which returns 400 error):

  - IOTA_PROVIDER_URL=http://172.17.0.1:4061/kk3

[AlvaroVega]

Depends on this PR #256
This PR should be merged after PR #256

[AlvaroVega]

time=2021-09-22T15:48:20.727Z | lvl=WARN | corr=eeed4c39-33d8-440a-8d52-8922230167f9 | trans=eeed4c39-33d8-440a-8d52-8922230167f9 | op=IoTAManager.Redirector | from=n/a | srv=smartcity | subsrv=/problemas/masproblemas | msg=several statusCodes [200,400] and combinedResults {"count":0,"devices":[]}, redirecting for GET | comp=IoTAgentManager