[#13122] Create cancel button for instructor request form

[NeoHW]

Fixes #13122

Outline of Solution

• Add a Cancel button next to the Submit button so users can undo their form request and return to the homepage.
• Added accessibility features to both cancel and submit button

UI changes

[itstrueitstrueitsrealitsreal]

LGTM, good that accessibility features for screen readers are also added.

[domoberzin]

LGTM

[mingyuanc]

@NeoHW same thing pls fix failing tests

[itstrueitstrueitsrealitsreal]

Hi @mingyuanc, noticed that tests have been failing for recent PRs due to docker-compose being upgraded, should we prioritise the merging of #13159 before other PRs?

[dishenggg]

LGTM!