Introduce `StringLike` enum (#9016)
## Summary
This PR introduces a new `StringLike` enum which is a narrow type to
indicate string-like nodes. These includes the string literals, bytes
literals, and the literal parts of f-strings.
The main motivation behind this is to avoid repetition of rule calling
in the AST checker. We add a new `analyze::string_like` function which
takes in the enum and calls all the respective rule functions which
expects atleast 2 of the variants of this enum.
I'm open to discarding this if others think it's not that useful at this
stage as currently only 3 rules require these nodes.
As suggested
[here](https://github.com/astral-sh/ruff/pull/8835#discussion_r1414746934)
and
[here](https://github.com/astral-sh/ruff/pull/8835#discussion_r1414750204).
## Test Plan
`cargo test`
