Deprecate isParameter, rename to isParameterDeclaration

[jakebailey]

This is a follow-up to #49929, which:

• Renames isParameterDeclaration to isPartOfParameterDeclaration. Done in another PR
• Renames isParameter to isParameterDeclaration (as that is the node name).
• Adds a deprecated compat function isParameter.
• Renames SyntaxKind.Parameter to SyntaxKind.ParameterDeclaration and adds a deprecated duplicate (like we did with JSDoc).

I made up the timing for this deprecation; I just copied the same scheme as another helper's but I feel like this one needs a loooot of time for people to fix.

This may not be the safest thing because isParameterDeclaration was previously a different function, so people may use the new one while still using old TS versions. Not great.

[jakebailey]

These values are made up and are up for discussion.

[DanielRosenwasser]

Yeah....SyntaxKind.Parameter is used quite a bit right now. We should probably have a very long warn period.

[jakebailey]

This comment is of course out of date, this missed 5.0 which was a shame.

I'm not totally sure what the plan here is anymore. I will note that we actually can't "remove" an enum item; there's not really a deprecation helper mechanism for that. So most people would work forever, it's just those who are using isParameter that will have a problem.

[jakebailey]

This models what we did for JSDoc.

[typescript-bot]

Looks like you're introducing a change to the public API surface area. If this includes breaking changes, please document them on our wiki's API Breaking Changes page.

Also, please make sure @DanielRosenwasser and @RyanCavanaugh are aware of the changes, just as a heads up.

[jakebailey]

I'm going to pull the isParameterDeclaration -> isPartOfParameterDeclaration rename into its own PR; it's confused enough people working on TS, but thankfully nobody externally is using it: https://github.com/search?q=%2F%5Cbts%5C.isParameterDeclaration%5Cb%2F+%28language%3ATypeScript+OR+language%3AJavaScript%29&type=code