Add type="button" to action buttons

postponed because current branch 1.1.x has target DSFR 1.12,
and DSFR 1.13 is still under progress (unreleased)

Hello @sourav_paul
Thank you for taking charge of this issue!
The changes look good except for the following file: templates/system/input--submit--search-submit.html.twig
This is an actual submit button, which will receive the type="submit" attribute, so it should be best to revert just this part

Hello @just_like_good_vibes
I initially associated the issue with DSFR v1.13 but this is actually an issue that already causes trouble whenever one of these components are inside a form, so I believe that it should be addressed regardless of the DSFR version

we need to address this more carefully, the initial work posted by sourav_paul did not carefully check for existing attributes in the tags.