[clang] [analyzer] Move alpha checker EnumCastOutOfRange to optin (PR #67157)

[Artem Dergachev via cfe-commits]

haoNoQ wrote:

> Before merging this PR, the diagnostics of the EnumCast checker should be updated to mention the name of the `enum` type in question. @gamesh411 could you create a PR that implements this improvement (as we discussed)?

Yes, it should call out the enum, call out the value, and then *track* the value (with `trackExpressionValue()`) in order to explain where it's coming from and why we think it's out of range.

https://github.com/llvm/llvm-project/pull/67157