Add Ats notice on sign in

[richardpattinson]

Trello card URL

https://trello.com/c/rsknc856/2367-hiring-staff-notice-upon-sign-in-for-ats-religious-app-forms

Changes in this PR:

We want to highlight our new ATS features and faith forms to hiring staff so want to advertise this on a service screen.

Question: Should this screen only appear when first signed in + a flag should be added as to whether the user has accepted the screen - or should it be displayed everytime?

Screenshots of UI changes:

Before

After

Checklists:

Data & Schema Changes

If this PR modifies data structures or validations, check the following:

• Adds/removes model validations
• Adds/removes database fields
• Modifies Vacancy enumerables (phases, working patterns, job roles, key stages, etc.)

If any of the above options has changed then the author must check/resolve all of the following...

Integration Impact

Does this change affect any of these integrations?

• DfE Analytics platform
• Legacy imports mappings
• DWP Find a Job export mappings
• Publisher ATS API (may require mapping updates or API versioning)

User Experience & Data Integrity

Could this change impact:

• Existing subscription alerts (will legacy subscription search filters break?)
• Legacy vacancy copying (will copied vacancies fail new validations?)
• In-progress drafts for Vacancies or Job Applications

[scruti]

I think some key bits are missing to turn this into an "acknowledge once" interstitial flow as the one it is replacing.

Also left a few suggestions around!

[github-actions]

Review app deployed to https://teaching-vacancies-review-pr-8330.test.teacherservices.cloud on AKS