[`pylint`] Show verbatim constant in `magic-value-comparison` (`PLR2004`) (#9694)
## Summary
Tweaks PLR2004 to show the literal source text, rather than the constant
value.
I noticed this when I had a hexadecimal constant, and the linter turned
it into base-10.
Now, if you have `0x300`, it will show `0x300` instead of `768`.
Also, added backticks around the constant in the output message.
## Test Plan
`cargo test`