Improve Record Selector UX

[seancolsen]

• Help content

  • Change title to "Pick a <table_name> Record"
  • Consider adding help text near the title that explains the affect the record selection will have within the parent context
  • Remove help text about keyboard actions, as hopefully the simpler UX now no longer necessitates it

• Creating a new record via the Record Selector

  • Headings to separate the new record for the existing records
  • Remove the "+NEW" thing because it's confusing and people think it's a button.
  • Add new column to the table which contains a "Pick" button for each row.
  • Experiment with putting the "Add new" UI below the results

• Nested selector

  • New "stacked modal" layout (done in Use stacked modals to display nested record selectors #1761)
  • Esc should close nested selector
  • Use a dark overlay instead of a light one, making it clearer that the background window is inactive.
  • Make the active FK cell peek through the overlay, improving aesthetics

• General

  • Automatically adjust column widths based on content
  • Hyperlink to table from within the title
  • Prevent scrolling page content behind modal #1871
  • Improve aesthetics during loading

• LinkedRecordInput

  • Disable hyperlinks
  • Don't open nested selector when clicking to clear value

• Results

  • Retain the results when the nested selector is open
  • Highlight matching cells using a background on the whole cell as well as a background on the matching substring text. Sometimes the matching text falls beyond the overflow and it's hard to tell which cells match and which don't.
  • vertical scrolling only for results
  • horizontal scrolling only for table
  • Use shadows to indicate when horizontal/vertical scrolling is possible
  • all cell should display as read-only. E.g. remove dropdown arrow for FK cells.
  • merge the keyboard highlighting behavior with the mouse highlighting behavior