[Canvas] Timepicker for last two hours

[shaunmcgough]

Canvas could benefit from having a time picker option for last two hours. This is a customer request. Much like the today feature rolled out in 7.3 this is a rolling two hour window.

[elasticmachine]

Pinging @elastic/kibana-canvas

[cqliu1]

Instead of adding this to the static list of options, I'm in favor of prioritizing making the time picker customizable as requested in #33867. That way users can set their own custom list of quick time ranges for the time filter element.