Fix for Data Quality perf and issue other tweaks.

[jdunkerley]

Pull Request Description

• Fix bug where DB_Table data quality indicators broke deserialization in the table viz.
• Memorization of the untrimmed data quality indicator and move to it being an operation and column function.
• If more than 10,000 rows then use a sample for untrimmed.
• ALIASes for blank functions.
• Fix for Snowflake drill down.
• Bug fix for Long and Double columns with Nothings at end.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.
• If meaningful changes were made to logic or tests affecting Enso Cloud integration in the libraries,
  or the Snowflake database integration, a run of the Extra Tests has been scheduled.
  • If applicable, it is suggested to paste a link to a successful run of the Extra Tests.

[AdRiley]

Is it possible to add tests for any of the new functionality?

[jdunkerley]

Is it possible to add tests for any of the new functionality?

Tests added for the table viz have been updated to cover the DB Table and sampled data quality indicator.
Will add a test for the column slice.

[radeusgd]

Looks good now, mostly some small nitpicks that I think may be worth adding but not necessary.

Only thing I'd like to fix before merging is the computation of countUntrimmed if the cached future was cancelled. Currently it runs on background thread but tries to fetch the context - that is bound to fail. We should just compute it on main thread if the background one was cancelled and it is being requested right now - deferring to background blocks the main thread until background thread is free to execute a new job, which may theoretically be a pretty long time.