Use client customization for keyvault-keys cryptography models

[maorleger]

As a first pass we copied various enums from the generated code to the hand-authored version in order to resolve some compatibility issues in naming and avoid breaking changes.

A better approach would be to use client.tsp customization to rename the keys as needed. This issue tracks:

1. Updating the client.tsp

2. Regenerating code

3. Removing the hand-authored version

          Yes, this is an accepted breaking [discussed here](https://github.com/Azure/autorest.typescript/issues/2832#issuecomment-2499507467) and we keep some special chars e.g underscore here between numbers or before/ending with numbers.
   

If you think the name here is not reasonable, you could use client name to rename.

@@clientName(JsonWebKeyCurveName.P256_K, "P256K", "javascript");

Also we are open to hear feedbacks for this breaking if you have any concern feel free to raise your concern in codegen issue.

Originally posted by @MaryGao in #31845 (comment)