Update java version to 21

[Dankoy]

Description

Updated java from 17 to 21.

Since in java 21 freemarker started to print new lines, I fixed it with <#t> tag.

Also added try-with-resources for executors.

Added spotless linter

Type of change

Please delete options that are not relevant.

• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Export new words from sqlite db. Shoud work correctly

Test Configuration:

• Firmware version: Windows 11
• Hardware:
• SDK: Oracle JDK 21.0.3+7-LTS-152

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules