add types to all the buttons in the angular.io examples to encourage
the best practice of always including a type per button (regardless
to whether it is in a form or now)
PR Close#44557
the aio examples have various eslint issues regarding template rules, those
are currently turned off and TODO comments have been added to them in the
examples eslintrc, fix such issues and remove the respective TODO comments
this also includes examples refactoring to use buttons for better accessibility,
this change tries to make the smallest amound of changes to the examples' behaviors
and designs/UI
PR Close#44557
