feat: return all available providers for collection

[jlahovnik]

In server mode all available providers of a collection sorted by priority are now returned at the collections endpoint (GET /collections, GET /collections/id)

[github-actions]

Test Results

       4 files  ±  0         4 suites  ±0   6m 38s ⏱️ ±0s
   431 tests +11     428 ✔️ +11    3 💤 ±0  0 ❌ ±0 
1 724 runs  +44  1 648 ✔️ +40  76 💤 +4  0 ❌ ±0 

Results for commit 010a60d. ± Comparison against base commit d824947.

♻️ This comment has been updated with latest results.

[github-actions]

Code Coverage (Ubuntu)

File	Coverage
All files	82%	✅

Minimum allowed coverage is 70%

Generated by 🐒 cobertura-action against 010a60d

[github-actions]

Code Coverage (Windows)

File	Coverage
All files	76%	✅

Minimum allowed coverage is 70%

Generated by 🐒 cobertura-action against 010a60d

[sbrunato]

if provider is specified by the user, search fallback will be disabled. So in this case, we should not return the full list, but only this provider

[jlahovnik]

if provider is specified by the user, search fallback will be disabled. So in this case, we should not return the full list, but only this provider

changed