Add support for MeterFilter#maximumAllowableTags

[philwebb]

See #13895 for background.

It would be nice to limit metrics collection for incoming requests to prevent out-of-memory errors.

/cc @jkschneider

[philwebb]

50/50 if this should be considered a bug or enhancement. I'll target to 2.0.x for now.

[snicoll]

Closing in favour of PR #14173