Small QoL improvements to MFA

[everettbu]

Mirror of supabase/supabase#43861
Original author: joshenlim

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Context

Resolves FE-2794

Just addressing some friction points i ran into when setting up MFA for my account under account preferences

Changes involved

• Hitting enter at each step of setting up MFA will submit and proceed (Previously didn't, had to click buttons)
• When logging in with MFA, automatically submit after entering 6 digits
• Refactored to use react hook form for AddNewFactorModal in FirstStep and SecondStep + simplified the logic a little

[github-actions]

🎭 Playwright Test Results

 156 passed
 1 flaky
 5 skipped

Details

 162 tests across 20 suites
 2 minutes, 31 seconds
 971e2a5

Flaky tests

Features › table-editor.spec.ts › table editor › filtering rows works as expected

Skipped tests

Features › assistant.spec.ts › AI Assistant › Can send a message to the assistant and receive a response
Features › sql-editor.spec.ts › SQL Editor › snippet favourite works as expected
Features › sql-editor.spec.ts › SQL Editor › share with team works as expected
Features › sql-editor.spec.ts › SQL Editor › folders works as expected
Features › sql-editor.spec.ts › SQL Editor › other SQL snippets actions work as expected