Implements both `StartExtractedFsDump` and `EndExtractedFsDump` commands into both nxdumptool and the Python host script.
Other changes include:
* poc: wake the write thread up if a preprocessing error occurs in all extracted FS dump functions. Fixes previously unhandled hangups.
* poc: verify current NCA hash before sending its last data chunk while dumping a NSP.
* host: update command handler to support CancelFileTransfer commands issued in-between SendFileProperties commands.
* host: update Markdown document.
* usb: use UsbCommandType_Count for the safety check in usbPrepareCommandHeader().
* usb: log both USB command header and command block whenever an error is reported by the host side.
dcd1f66790