Added greater granularity for boolean environment variables

[alessandrodetta]

Changes Proposed

See suggestion in #510.

I preferred to issue this pull request as draft because this is my first open source pull request.

I will suggest in the future anyway to add implementation for some kind of structure (maybe a map?) to store parsed environment variables for both boolean and strings (in already created env.go) so that the environment variables are parsed for their correct values in one single point in code and not sparsely in different files as it is now and also so that reading multiple times their values doesn't involve more calls to the OS.

Furthermore, somehow I would also suggest integrating the management of program options into this reasoning, in order to clearer management since in some cases there is a relationship between the two.

Check List

• [x] The title of my pull request is a short description of the changes
• [x] This PR relates to some issue: Closes #510
• [ ] I have documented the changes made (if applicable)
• [x] I have covered the changes with unit tests

[undera]

As for CI failure, try merging from master, I have updated golang version to 1.21 there

[alessandrodetta]

@undera Probably you got notified, but I have updated the solution with the changes you reviewed. I have rebased the feature branch so that now is on top of the current main branch so that I don't need to re-create a PR. Your idea was to create a new PR with my changes from main itself or like this is ok?

[codecov-commenter]

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Codecov Report

Attention: Patch coverage is 66.66667% with 4 lines in your changes missing coverage. Please review.

Project coverage is 30.18%. Comparing base (3d7f907) to head (4aeec65). Report is 24 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/dashboard/server.go	0.00%	2 Missing :warning:
pkg/dashboard/api.go	0.00%	0 Missing and 1 partial :warning:
pkg/dashboard/objects/data.go	0.00%	1 Missing :warning:

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #511 +/- ## ========================================== + Coverage 29.72% 30.18% +0.46% ========================================== Files 10 10 Lines 1329 1335 +6 ========================================== + Hits 395 403 +8 + Misses 893 891 -2 Partials 41 41 ```

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[undera]

Please do another pull from master, there is small issue with static check setup in CI

[undera]

Awesome! Thanks!