[Lint] Also catch log! and log_chronik! in .rs files in LogLinter

Summary:
Missing \n at the end of log! and log_chronik! macro invocations in Rust files are now reported by LogLint.

Since string literals in Rust are allowed to contain newline characters, we need to insert a \s into the regex.

Test Plan:

1. Remove the 4 \n in chronik-http/error.rs
2. arc lint
3. 4 errors are emitted

Reviewers: Fabien, #bitcoin_abc

Reviewed By: Fabien, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D13556