Improve Full GC traces

In DocumentBlobManagerComponent#deleteBlob, the following logs should be at the same level with or without the dryRun mode:

• "Blob: {} from repository: {}, provider: {} cannot be deleted" – info level
• "Blob: {} from repository: {}, provider: {} can be deleted" – info level but only in dryRun
• "Deleting blob: {} from provider: {}" – debug level we could have "Blob: {} from repository: {}, provider: {} is deleted" at info level

Also the sampling is activated only on dryRun mode and only for deleted docs, we want to assert both deleted and not deleted blobs, and we want to sample docs even if not in dry mode.

if (dryRun && deleted && ++sampleCounter % sampleModulo == 0) {

Should be

if (++sampleCounter % sampleModulo == 0)

and trace should reflect if we are in dryRun or not