Add diagnostic management client
Bug fixes for Shoebox - Merged from Hydra-spec-pr
Insight management updates
More filter updates (copied from hydra-spec)

- Fixes to regex parser
- Fixes to expression parser
- Fix MetricDefinitionOperations from requiring filter string
- Throw exception instead of returning bad request in client
- Minor DateTime format fix
Bug fixes in Metrics client and update

- New event functions not moved to azure-sdk-for-net from hydra-specs-pr
repo
Null filter fix from hydra-spec
Add Event customizations to csproj
Update namespace for event parameters
Unify key encoding function (from hydra-spec)

Also minor cosmetic changes and update to management client and event
namespaces
Add management changes
Type fixes for Count and scheduledTransferPeriod
Fix localized values in metric
Metric Unit is always count

fix: copy over unit value from definition
BUG: 1886832 and other fixes from hydra-spec
Passthrough change and missed includes
Need to set status code
merge from dev