[Design]: Uptake type declaration expressions in typespec-azure

Regarding: https://github.com/microsoft/typespec/pull/11019

The new experimental type expressions feature allows:
- declaring types inline during usage for *most* typespec types (including named unions, enums, scalars)
- decorating type expressions

This presents opportunities for us to simplify the representation of many types and to make library types more efficient, but the feature could also be misused by spec authors and so will require new documentation and new safeguards.

- Changing many type declarations and template declarations in typespec-azure-core and typespec-azure-resource-manager into aliases
- Adding best practice documentation on when top use type expressions
- Alias definitions
- Decorator arguments
- Template Arguments
- Adding linting rules that enforce best practices
- Prevent usage in wire types (until naming is allowed)