HPCC-10979 Fix custom tributton control handling of tab and spacebar

Allow tributton to recieve focus, and move on to next tabindex when tab
key is pressed.  Rotate tributton state when spacebar is pressed.

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #5571 from afishbeck/triButtonTab

HPCC-10979 Fix custom tributton control handling of tab and spacebar

Reviewed-By: Kevin Wang <kevin.wang@lexisnexis.com>
Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>