Update to latest Bicep Core libraries (1.264.0)

[JohnathonMohr]

Description

• Updating Bicep libraries current stable versions.
  • Conforming to breaking changes introduced in the latest version.
• Updating other utility libraries
• Fixing some data tests (newer MSTest version was failing for some of them)

---

This checklist is used to make sure that common guidelines for a pull request are followed.

• I have read the contribution guidelines.
• The pull request does not introduce breaking changes.

General Guidelines

• Title of the pull request is clear and informative.
• Description of the pull request is clear and informative.
• I have added myself to the 'assignees'.
• I have added 'linked issues' if relevant.

Testing Guidelines

• Pull request includes test coverage for the included changes.