enhancement: Support SSL broker connections in worker

[srinjoydutta03]

Description

Added support for SSL connections for broker/backend.

Related PR and Issue

This PR follows the changes made in the helm charts (repository-service-tuf/helm-charts#42).
Issue: #709

CC: @kairoaraujo

[srinjoydutta03]

Hi @kairoaraujo, sorry for the oversight of not running the pre-commit checks. I have fixed them.

[codecov]

Codecov Report

Attention: Patch coverage is 55.55556% with 4 lines in your changes missing coverage. Please review.

Project coverage is 74.68%. Comparing base (714a29d) to head (71307b0).
Report is 195 commits behind head on main.

Files with missing lines	Patch %	Lines
app.py	55.55%	4 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (714a29d) and HEAD (71307b0). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (714a29d)	HEAD (71307b0)
	2	1

Additional details and impacted files

@@             Coverage Diff              @@
##              main     #750       +/-   ##
============================================
- Coverage   100.00%   74.68%   -25.32%     
============================================
  Files           15       14        -1     
  Lines         1071     1513      +442     
============================================
+ Hits          1071     1130       +59     
- Misses           0      383      +383     

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[kairoaraujo]

Thank you for the contribution @srinjoydutta03

Things I would like to see in this PR:

• Documented the environment variables on docs/source/guide/Docker_README.md
• Unit Tests for the changes in tests/unit/test_app.py

As we are currently on RC state for 1.0.0, I will create a branch 1.1.0dev.

[srinjoydutta03]

Hi @kairoaraujo I have added the tests and docs, along with a few minor changes in other files to make sure it all works as expected.

[srinjoydutta03]

@kairoaraujo Could you please review them and tell me if any more changes are required? Thanks :)