Updater: change excluded repos handling

[sale3]

Description (e.g. "Related to ...", etc.)

Target repo exclusion is set only in clone operation and the pattern is stored in last_validated_commit file.
Excluded target repos' last validated commits are set to None.
--exclude-target is removed in favor of --exclude-filter.
--exclude-filter is extended to filter repos by name to match --exclude-target implementation.

In auth_repo.py:
Removed excluded repos handling for methods targets_data_by_auth_commit and sorted_commits_and_branches_per_repositories since it is not used anywhere. Introducing --exclude-filter would lead to coupling with repositoriesdb.

Tests:
Removed test_update_after_update_with_exclude, test_update_after_update_with_exclude_with_invalid_commit and test_full_update_after_partial_update since update with exclude is no longer feasible.
Added verification for expected last_validated_commit entires - verify_excluded_lvc_entries function.

Closes: #716

Code review checklist (for code reviewer to complete)

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Commit messages are meaningful (see this for details)
• Tests have been included and/or updated, as appropriate
• Docstrings have been included and/or updated, as appropriate
• Changelog has been updated, as needed (see CHANGELOG.md)

[renatav]

This assert does not really check anything given the if condition. Maybe if excluded: assert "exclude_filter" in last_validated_data else assert exclude_filter" not in last_validated_data would be more useful.

[sale3]

mypy was complaining if there was no null check, so that's why I put it like that.

[renatav]

This was my old way of handling this, so without saving exclude_filter. Just look for repositories not in last_validated_data and skip them. If are going to start storing exclude_filter, we should either validate rely on it primarily and just check if repositories not in last validated data and not on disk match the filter? What if there is a discrepancy here? Do we even need excluded_target_globs if we have exclude_filter? I added that automatic detection of excluded target repositories since there was no way to read this information.

[sale3]

I just realized that we can get rid of this completely. I think that it's not likely to happen that repositories.json doesn't have one of the target repos as an entry?

[renatav]

It very unlikely, but I wouldn't make that assumption.

[CLAassistant]

All committers have signed the CLA.

[renatav]

Tested and works well. Found a minor edge-case, might not even be addressing now. When you clone with an exclude-filter and then remove the filter line from the last_validated_commit file and run update, it clones the missing repository but prints All repositories are up-to-date with no changes or errors.