Add LST resource module

[stalabi1]

SUMMARY

I added a new resource module for link state tracking, LST.
Please see model PR.

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

sonic_lst

OUTPUT

Updated regression results:
regression-2024-12-19-09-04-09.html.pdf

regression-2024-10-14-14-18-15.html.pdf
diff_output.log
merge_check_mode.log
delete_check_mode.log
delete_upstream_group_check_mode.txt
facts_gathering.log

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have maintained backward compatibility or have provided any relevant "breaking_changes" descriptions in a "fragment" file in the "changelogs/fragments" directory of this repository.
• I have provided a summary for this PR in valid "fragment" file format in the "changelogs/fragments" directory of this repository branch. Reference : Ansible Change Log Document

[awhaley-dell]

This module looks good on first pass. The only notes I have are style based regarding docstring triple quotes being on their own line separated from the function description by a newline.

[ArunSaravananBalachandran]

dict.get can be used to populate default values.

Suggested change

	if all_evpn_es_downstream:
	group_dict['all_evpn_es_downstream'] = all_evpn_es_downstream
	else:
	group_dict['all_evpn_es_downstream'] = False
	if all_mclags_downstream:
	group_dict['all_mclags_downstream'] = all_mclags_downstream
	else:
	group_dict['all_mclags_downstream'] = False
	group_dict['all_evpn_es_downstream'] = config.get('all-evpn-es-downstream', False)
	group_dict['all_mclags_downstream'] = config.get('all-mclags-downstream', False)

[stalabi1]

Addressed.

[ArunSaravananBalachandran]

Please handle scenario when 'have' is subset of 'want'. (nothing to delete, but new config is to be added)

[stalabi1]

Addressed.

There are several modules that don't account for this case so those modules will need to be fixed.

[ArunSaravananBalachandran]

Since this option specifies the name of the interface, could it be changed to 'name' ?

[stalabi1]

Addressed.

[kerry-meyer]

This change set, the accompanying set of tests, and the test results look good. I am posting only a few minor requests for changes.

[kerry-meyer]

Thank you for making the requested changes.

All proposed changes, test cases, and corresponding test results look good after the latest commit.

Approved.