RAS-1614: Fix Frontstage request_password_change logic

[SteveScorfield]

What and why?

A bug was found where if a user tries to reset their password multiple times and let the token expire. As a result, the token was deleted (null value) in the DB and then a 500 was shown to the user as a result of a conditional. The fix introduced will prevent this from happening. I've added more tests to cover further scenarios around password resetting.

Note: I think I have covered all potential unit test scenarios but let me know if you see other areas.

How to test?

1. Build out your dev env
2. Run acceptance tests
3. Navigate to the 'Forgot password' page
4. Enter an email of a user you know is in the DB
5. You should receive the usual reset password message
6. Using a DB tool of you choice, goto the 'respondent' table of the 'partysvc' schema
7. Locate the ID of the user, then using the 'UPDATE SET' SQL commands, set the 'password_verifcation_token' value to 'NULL'
8. Navigate back to 'Forgot password' page and enter the same email. You should receive 'An error has occurred' message
9. Next deploy this PR to your dev env
10. Navigate back to the 'Forgot password' page and enter the same email
11. You should get the correct 'Check your email' message page

Run unit and acceptance tests

Jira

https://jira.ons.gov.uk/browse/RAS-1614

[SteveScorfield]

/deploy scorfs

[ras-rm-pr-bot]

Deploying to dev cluster with following parameters:

• namespace: scorfs

• tag: pr-1063

• configBranch: main

• paramKey: ``

• paramValue: ``

[matthew-robinson-ons]

The implementation works to resolve this issue found. Some queries around the testing

[matthew-robinson-ons]

Happy this fixes the bug and testing is improved

[LJBabbage]

Realistically we shouldnt be client testing and it should be at function level, however the code is sub optimal as the view shouldn't be doing all this and should be rationalised properly. We don't have to change this now mind.

[SteveScorfield]

/deploy scorfs

[ras-rm-pr-bot]

Deploying to dev cluster with following parameters:

• namespace: scorfs

• tag: pr-1063

• configBranch: main

• paramKey: ``

• paramValue: ``

[SteveScorfield]

/deploy scorfs

[ras-rm-pr-bot]

Deploying to dev cluster with following parameters:

• namespace: scorfs

• tag: pr-1063

• configBranch: main

• paramKey: ``

• paramValue: ``

[SteveScorfield]

/deploy scorfs

[ras-rm-pr-bot]

Deploying to dev cluster with following parameters:

• namespace: scorfs

• tag: pr-1063

• configBranch: main

• paramKey: ``

• paramValue: ``

[LJBabbage]

A bit of redundancy in the tests, but it seems to work