Implement FileListMetaDataProvider
This MR implements FileListMetaDataProvider
that can be used to load metadata for multiple files at same time using multiple threads. It will be used by system/dolphin!522
It relies on FileMetaDataProvider
for metadata loading functionality itself.
FileListMetadataScheduler
is implemented to manage/optimize tasks.
This MR depends on !63 !60 !61 !62 !29 !31 (all included here). Basically this MR is just the last commit 7178d831c80c4b0d89faa0731e152b5ed0644169
FYI: @meven