feat: GEO-937 admin announcements page frontend

[banders]

Description

Implemented (most of) the admin frontend's "announcements" page. The only functionality not implemented is the behaviour of the "action" links, which are described in separate jira tickets.

Fixes # GEO-937

There's also a new .sql script which can inject fake announcements into the database for testing:
psql -U fin-pay-transparency -f .\backend\db\sample-data\generate_fake_announcements.sql

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

New unit tests

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have already been accepted and merged

---

Thanks for the PR!

Deployments, as required, will be available below:

• Frontend
• Admin Frontend
• Backend external API console

Please create PRs in draft mode. Mark as ready to enable:

• Analysis Workflow

After merge, new images are deployed in:

• Merge Workflow

---

Thanks for the PR!

Deployments, as required, will be available below:

• Frontend
• Admin Frontend
• Backend external API console

Please create PRs in draft mode. Mark as ready to enable:

• Analysis Workflow

After merge, new images are deployed in:

• Merge Workflow

---

Thanks for the PR!

Deployments, as required, will be available below:

• Frontend
• Admin Frontend
• Backend external API console

Please create PRs in draft mode. Mark as ready to enable:

• Analysis Workflow

After merge, new images are deployed in:

• Merge Workflow

---

Thanks for the PR!

Deployments, as required, will be available below:

• Frontend
• Admin Frontend
• Backend external API console

Please create PRs in draft mode. Mark as ready to enable:

• Analysis Workflow

After merge, new images are deployed in:

• Merge Workflow

[sonarcloud]

Quality Gate passed for 'Pay Transparency backend-external'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed for 'Pay Transparency Frontend'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed for 'Pay Transparency Backend'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed for 'Pay Transparency admin-frontend'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
81.3% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed for 'Pay Transparency doc-gen-service'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud