feat(rust/rbac-registration): Introduce Cip0134UriSet type

[stanislav-tkach]

Description

• The Cip0134UriSet type was added.
• Option<Vec<_>> fields of the Cip509RbacMetadata structure were changed to Vec<_>.
• Error handling becomes stricter.

Related Issue(s)

Closes #104.

Description of Changes

I have renamed Cip0134UriList to Cip0134UriSet because I don't think that "list" is a proper description for the current structure.

This pull request should be merged into the rbac-registration-improvements branch instead of main. The goal is to have separate smaller incremental changes that can be reviewed together in a separate pull request (from rbac-registration-improvements to main).

Please confirm the following checks

• 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 module

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 229/229}$ | ${\color{red}Fail: 0/229}$ |