ui: move `latestQuery`, `latestFormattedQuery` from redux to local state

[xinhaoz]

trafficstars

Previously, the fields latestQuery and latestFormattedQuery representing the latest non-empty query string for a statement viewed from the detaisl page was being stored in redux. The purpose of these fields was to preserve the query when changing tabs in the stmt details page. Saving this in the redux store was unnecessary and so this commit moves these fields to the stmt details local state.

Release note: None

[cockroach-teamcity]

This change is 

[xinhaoz]

Yes, that behaviour is still preserved here, we're doing the exact same thing but in the component state instead of redux since this info isn't needed anywhere else in the app. The state is only updated if we receive a different, non-empty query. Included a loom!

[xinhaoz]

bors r+

[craig[bot]]

Build succeeded:

• Bazel Essential CI (Cockroach)