add option of setting the user_assigned_identity_id name

[nellyk]

Description

Closes #147

Type of Change

• Non-module change (e.g. CI/CD, documentation, etc.)
• [ x ] Azure Verified Module updates:
  • [ x] Bugfix containing backwards compatible bug fixes
    • [ x] Someone has opened a bug report issue, and I have included "Closes #{bug_report_issue_number}" in the PR description.
    • The bug was found by the module author, and no one has opened an issue to report it yet.
  • Feature update backwards compatible feature updates.
  • Breaking changes.
  • Update to documentation

Checklist

• [ x] I'm sure there are no other open Pull Requests for the same update/change
• [ x] My corresponding pipelines / checks run clean and green without any errors or warnings
• [x ] I did run all pre-commit checks

Copilot reviewed 1 out of 3 changed files in this pull request and generated no comments.

Files not reviewed (2)

• main.tf: Language not supported
• variables.tf: Language not supported

[kewalaka]

the variable is called id, description references an id, but it is setting a name?

I have proposed a broader mechanism to do this in #161

[nellyk]

the variable is called id, description references an id, but it is setting a name?

I have proposed a broader mechanism to do this in #161

you're right ideally this should be a name and note reference an "id" i'll update the repo