feat(metrics): add more fine grained metrics for distinguishing between request sources

[RyanHolstien]

Adds the following metrics:

• Accurate ingestProposal metric that accounts for batch sizes. Also splits into several metrics with sync/async + source API. These can be filtered with PromQL using "...ingestProposal_sync.", "...ingestProposal_async.", "...ingestProposal_sync_GRAPHQL", etc.
• Finer grained metric for GraphQL based on user agent to allow for tracking true UI errors vs programmatic clients using GraphQL
• Full MCL, MCP, & PE produce count
• Preprocess count for UI based ingestion (things that skip waiting for MCL to be in ES indices)

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub