feat: geo 983 get api for objectstorage get files

[goemen]

Description

Implementing announcements file download

Fixes # (issue)

Type of change

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

Checklist

• I have read the CONTRIBUTING doc
• 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

Further comments

---

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[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
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
84.1% 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
91.7% 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