Make a single set of decorators that work in TypeScript with experimentalDecorators set to either true or false, and in Babel with version equal to "2023-05" by duck-typing the decorator arguments.

After this effort we will have one set of decorators that work under the following cases:

1. TypeScript with experimentalDecorators: true and no accessor keyword
2. TypeScript with experimentalDecorators: true and accessor keywords
3. TypeScript with experimentalDecorators: false and accessor keywords
4. Babel with experimentalDecorators: false and accessor keywords

The trade-off is that we have to have the same behavior in each configuration:

• We can't skip reflection for initial property values
• We have to wrap accessors as we can't detect the difference between auto-accessors and hand-written accessors with experimental decorators

Tasks:

• Make legacy-decorators work with experimentalDecorators: false and pass the std-decorators tests ([reactive-element] 3.0 hybrid decorators #4140)
• Unify the behavior
  • Reflect initial property values to attributes ([reactive-element] Make standard property decorator reflect initial values #4145)
  • Always wrap accessors ([reactive-element] Always wrap user accessors #4146)
• Remove std-decorator and legacy-decorator files, but not std-decorator tests.
• Run decorators against std-decorator tests with experimentalDecorators: true.
• Re-enable Babel tests when [Bug]: Decorator metadata is not implemented babel/babel#15889 is fixed.
• Add a compiler-time flag to choose one or both decorator implementations to enable code elimination
• Ensure we have tests for noAccessor: true in all cases
• Deprecate and add a dev-mode warning for overrides of createProperty and getPropertyDescriptor