Add FS::info64 call for fielsystems > 4GB

[earlephilhower]

Fixes #6082

Add an info64() call which returns used and total sizes as 64 bit
quantities. A default wrapper that just copies the 32-bit values is
included for LittleFS/SPIFFS which can't hit those capacities.

[d-a-v]

agree with @devyte's comments, other than that: LGTM

[devyte]

Minor nitpick: The LittleFS and SPIFFS info64() are wrong for > 4GB because they go through the 32b info(). Doesn't matter because ESPs with such flash size don't exist, but in theory it could be possible to decouple the FS from the underlying storage (work ongoing elsewhere), and then you could instantiate on some other media.
Maybe add a comment about it?
Not a stopper or anything so approving.

[earlephilhower]

While it may be possible to do a multiGB LittleFS or SPIFFS, I think they'd both fall over and die right now because of the assumptions they're baked into things. Like defining sizes in terms or int32 everywhere. If some decoupling occurs (it could today, just shim the flash_write to do SPI writes to an external chip) we can definitely revisit this, but my guess is they'd need to rewrite LFS/SPIFFS on-chip format in an incompatible way so would end up making a "new" FS anyway...