Reinstate bulk sms limit

[whabanks]

Summary | Résumé

This PR reinstates bulk sms validation code that was reverted in this PR due to issues with the added validation firing on bulk emails as well.

Related Issues | Cartes liées

cds-snc/notification-utils#294
cds-snc/notification-api#2169

Test instructions | Instructions pour tester la modification

Set up

• SMS template with 1 variable and some content.
• SMS template with 2 (or more) variables and some content
• Create CSVs with some rows where the variables do not exceed 612 characters, and some rows that do.

Test 1

1. Try to send using the CSV's that go over the limit for both templates
2. Note that an error message is displayed at the top of the Edit your spreadsheet screen
3. Note that inline error messages are displayed on the cells with variable content indicating the length limit.

Test 2

1. Change the CSV's so there are no more errors
2. Re-upload and verify that normal sending still functions as expected.

[github-actions]

🧪 Review environment

https://xp2fvbvxbtukzzopjat6xk2daa0vjcty.lambda-url.ca-central-1.on.aws/