Filter metrics containing invalid characters in Mimir remote_write config

In the umbrella repository: https://repo1.dso.mil/big-bang/bigbang/-/blob/master/chart/templates/monitoring/values.yaml?ref_type=heads#L232

Set up a config to drop all mimir invalid characters if mimir is enabled, akin to what is done here: https://repo1.dso.mil/big-bang/team/deployments/bigbang/-/merge_requests/611/diffs#03700cc0357b7246a6695004430b5777c02554b3_479_481