fix(filters) Fix issues with structured properties filters

[chriscollins3456]

Fix a few issues we were seeing with structured properties that have dots in their IDs:

• we were passing in the converted field name for structured props into toElasticsearchFieldType which would not match with a structured property entity definition since the field name strips dots and replaces them with underscores. Therefore we were always defaulting to STRING - now use the criterion field which doesn't have dots removed.
• When there were no matches, we were just returning the converted elastic field name back to the UI which we could not resolve to a structured property entity if there were dots in it. In this case, return the criterion field instead.

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

[jjoyce0510]

So long as David also acked these changes, LGTM