feat: DAH-3110 make enter submit

[tallulahkay]

Description

Allow pressing enter to submit the sign in form.

Jira ticket

https://sfgovdt.jira.com/browse/DAH-3110

Checklist before requesting review

Version Control

• branch name begins with angular if it contains updates to Angular code
• branch name contains the Jira ticket number
• PR name follows type: TICKET-NUMBER Description format, e.g. feat: DAH-123 New Feature

Code quality

• the set of changes is small
• all automated code checks pass (linting, tests, coverage, etc.)
• code irrelevant to the ticket is not modified e.g. changing indentation due to automated formatting
• if the code changes the UI, it matches the UI design exactly
• if the changes include human translations, follow the human translations process

Review instructions

• instructions specify which environment(s) it applies to
• instructions work for PA testers
• instructions have already been performed at least once

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[cliu02]

Great workaround until we update UIC Form!

[fwextensions]

This won't work if the component is only rendered once, since they'll be undefined the first time through (though there seem to be enough extra renders that this isn't an issue in practice).

Still seems like just using a basic <form> here is the simplest one-line fix.

[tallulahkay]

What I need from you is to PA test. If you can't or won't, I'll either ask someone else to or close this ticket and pr.