Force 2FA code input to show only numeric keyboard on touch devices

What does this MR do?

This MR adds inputmode to 2FA code input field such that it forces touchscreen device to show a numeric-only keyboard for code input (as 2FA codes are numeric only). Inspiration for this MR comes from this article.

Screenshots

Before	After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related Issue

#20605 (closed)

changed milestone to %12.7

added UI polish featureenhancement frontend labels

assigned to @kushalpandya

unmarked as a Work In Progress

Reviewer roulette

Changes that require review have been detected! A merge request is normally reviewed by both a reviewer and a maintainer in its primary category (e.g. frontend or backend), and by a maintainer in all other categories.

To spread load more evenly across eligible reviewers, Danger has randomly picked a candidate for each review slot. Feel free to override this selection if you think someone else would be better-suited, or the chosen person is unavailable.

Once you've decided who will review this merge request, mention them as you normally would! Danger does not (yet?) automatically notify them for you.

Category	Reviewer	Maintainer
frontend	Ezekiel Kigbo (@ekigbo)	Martin Wortschack (@wortschi)

Generated by Danger

added backstage [DEPRECATED] label

@iamphill Can you review and merge this small MR please?

assigned to @iamphill

@kushalpandya Minor question

unassigned @iamphill

assigned to @iamphill

approved this merge request

resolved all threads

merged

mentioned in commit 7c15fffd

changed the description

mentioned in issue #20605 (closed)

mentioned in issue #196812 (closed)

mentioned in commit 5681fecf

mentioned in issue #198352

mentioned in merge request !23514 (merged)

changed the description

added typefeature label

mentioned in issue #207562 (closed)