What this PR does

This PR fixes an issue where the MQE benchmarking tool could run benchmarks that did not match the provided filter, or run multiple benchmarks in the same process, producing incorrect peak memory consumption data.

This happens because go test's -bench flag takes the value provided and splits it on /, then treats each part as a separate regex. This is problematic when using a name like BenchmarkQuery/a_100, instant query/engine=Mimir, as this will match any benchmark with a_100, instant query in the second part (eg. 1 + a_100, instant query). So we need to ensure that each part is set to match the full string of that part.

Which issue(s) this PR fixes or relates to

(none)

Checklist

• [n/a] Tests updated.
• [n/a] Documentation added.
• [covered by Mimir Query Engine #10067] CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX].
• [n/a] about-versioning.md updated with experimental features.