Request this branch be merged to master for next release

Hi @sid88in , @bboure , could you merged this branch to master for the next release ?

Commit message amended to follow semantic release

Hi @sid88in @bboure , I was hoping to get this change released. Wanted to know if you planning a release soon and if there is anything I need to do to ensure this is included ?
Thanks !

@DoyleBrendan, please fix merge conflicts.

Fresh PR - #711

Thanks for this, @DoyleBrendan — enhanced metrics is a genuinely useful addition and your structure made it easy to pick up. I've opened #711 to carry it forward, since this branch had drifted a long way from master (100+ commits, plus a jest 27→30 bump) and an in-place update wasn't practical. Your work is credited as co-author on the commit.
A few things I corrected while bringing it up to date, for transparency:

OperationLevelMetricsConfig had a leading space in ' DISABLED' (type + validation), so the correct AWS value DISABLED was actually being rejected — fixed.
AWS requires all three EnhancedMetricsConfig fields, so the schema now requires them (an empty config was passing validation but would fail at deploy).
ResolverLevelMetricsBehavior is now read from config instead of being hardcoded.
The per-resolver MetricsConfig: DISABLED was being written onto every resolver for every user, which both changed existing stacks' templates and meant resolver metrics could never be turned on. It's now emitted only when enhancedMetrics is set, and a new optional metricsConfig lets you enable it per resolver.

I also added unit + e2e (CloudFormation synthesis) coverage for the API- and resolver-level behavior. Closing this in favor of #711 — please take a look there, and thank you for kicking it off.