feat: inline dataloading

[ndr-brt]

What this PR changes/adds

Inline extensions/dataloading method moving its content to the spi.
Remove unused data-loader-cli launcher

Why it does that

Cleanup

Further notes

• Got rid of the DataSink interface, as its name could be misleading since there's another DataSink interface in the data-plane-spi
• Cleaned up a little the AssetIndex and ContractDefinitionStore hierarchies, but in the future I would get rid also of the AssetLoader and ContractDefinitionLoader interfaces as they are not useful anymore. Seemed too much for this PR, probably better to do that after the project structure review.

Linked Issue(s)

Closes #1833

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• assigned appropriate label? (exclude from changelog with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and styleguide for details)

[codecov-commenter]

Codecov Report

Merging #1846 (278d172) into main (efe29b3) will decrease coverage by 0.08%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #1846      +/-   ##
==========================================
- Coverage   62.50%   62.41%   -0.09%     
==========================================
  Files         781      777       -4     
  Lines       16640    16545      -95     
  Branches     1085     1078       -7     
==========================================
- Hits        10401    10327      -74     
+ Misses       5789     5770      -19     
+ Partials      450      448       -2     

Impacted Files	Coverage Δ
...r/core/controlplane/ControlPlaneCoreExtension.java	0.00% <ø> (ø)
...lplane/defaults/assetindex/InMemoryAssetIndex.java	92.72% <ø> (ø)
...or/api/datamanagement/asset/AssetApiExtension.java	100.00% <ø> (ø)
...datamanagement/asset/service/AssetServiceImpl.java	100.00% <ø> (ø)
...ractdefinition/ContractDefinitionApiExtension.java	100.00% <ø> (ø)
...inition/service/ContractDefinitionServiceImpl.java	100.00% <ø> (ø)
...ceconnector/assetindex/azure/CosmosAssetIndex.java	89.18% <ø> (ø)
...or/assetindex/azure/CosmosAssetIndexExtension.java	0.00% <ø> (ø)
.../store/CosmosContractDefinitionStoreExtension.java	0.00% <ø> (ø)
...taspaceconnector/sql/assetindex/SqlAssetIndex.java	0.00% <ø> (ø)
... and 5 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.