fix(btn): remove admin sms toggle check

[KenLSM]

Problem

Missed out the whole backend changes for #7257.

Also took the chance to update backend tests.

Closes FRM-1716

Solution

Key logic changes were the removal of checks that will:

1. Disable SMS (processAdminSmsCounts, disableVerifiedFieldsIfRequired)
2. Block OTP Verification toggle on updates from FormFE (shouldUpdateFormField)

Breaking Changes

• No - this PR is backwards compatible

Tests

Regression

Admins can update twilio credentials

• Create a new storage form
• Go to Form Twilio Settings page
• Enter ACC, SKK, SKK, MGG for the respective fields
• Ensure that clicking on save credentials isn't blocked

Admins can update OTP fields

• Ensure that clicking on "Remove and re-enter credentials" isn't blocked

Respondent OTP verification still works

• Add Mobile field
• Enable OTP verification
• Open up the admin form
• Ensure that verify sends an SMS to you

New feature test

• Update on SSM SMS_VERIFICATION_LIMIT to 10
• Send 10 SMS
• Ensure that the 11th SMS is still received by respondent
• Ensure that admin can still toggle on and off OTP verification field

[linear]

FRM-1716 BTN | Remove 10k sms limit

[justynoh]

lgtm