RPC: Add TarExtract command, some small fixes

[Willy-JL]

What's new

• RPC storage command to extract tar file to destination (needs Storage: TarExtract request flipperzero-protobuf#50, probably need to update submodule if/when it is merged)
• Fixed extract failing if not extracting at /ext or /int, this is because first directory entry in tar is / and path_concat() would result in /path/to/dest/ with trailing slash. This is a basic fix but might be worth changing the behavior of the path library in such edge cases?
• Added some missing storage state resets, all other functions had them so it seemed like they should be there, revert if i misunderstood :D

Verification

• Storage operations, backup and restore, work fine over RPC
• Tar files (like resources.tar, so USTAR format) can be extracted to chosen destination (not sure on easiest way to make one-off RPC calls to test)

Checklist (For Reviewer)

• PR has description of feature/bug or link to Confluence/Jira task
• Description contains actions to verify feature/bugfix
• I've built this code, uploaded it to the device and verified feature/bugfix

[gsurkov]

@Willy-JL

not sure on easiest way to make one-off RPC calls to test

We have some python scripts for that purpose which can be found here.

In the meantime, I've added support for TarExtractRequest at flipperdevices/flipperzero_protobuf_py#25