[Feature Request]: Add Support for Limiting Function Length (Max Line Count) #348

I would like to request a new feature for cpplint: the ability to enforce a maximum function length (number of lines per function). This would help teams maintain readability and prevent overly long functions that are harder to maintain and understand.

Use Case:

This would be useful in scenarios where code maintainability and readability are a priority.
Having a configurable rule to enforce a limit on function size would help catch long functions early in the review process.

Expected Behavior:
A new configurable rule or check that allows users to specify a maximum number of lines allowed per function.
For example, something like:

`cpplint --max-function-lines=25 your_file.cpp`

Additional Information:

• This feature would align with best practices for clean, maintainable code.
• It could be useful in both C++ and C projects.

Thanks!