fix: useViewportData - memoize subscriptions and first row of viewport

[bmingles]

fixes #2003 - useViewportData - re-subscribes to table any time ViewportData changes

• Memoized dh.Table.EVENT_SIZECHANGED handler
• Memoized dh.Table.EVENT_UPDATED handler

fixes #1928 - useViewportData - setViewport should maintain last firstRow value when table size changes

• Track last set "first row" to be re-used when table size changes but table reference remains the same

Tested

• Ticking table
  • table update subscriptions no longer occur on each viewportData change
  • size change handler no longer re-subscribes on every render
• ACL Editor - scrolling viewport data still works. Filtering still properly resets viewport to zero