Fix Ender 3 V2 Power Loss Recovery

[thinkyhead]

Ender 3 V2 user interface code is still a work-in-progress. This PR fixes issues with Power-Loss Recovery and brings it up to date with support for SD card sub-folders.

• Fix an issue where files in sub-folders were prevented from resuming.
• Set the long filename in response to card.fileExists() so the correct name displays on the "Resume" screen.
• Update the UI to put "Cancel" on the left, "Continue" on the right, with counter-clockwise selecting "Cancel."
• Re-draw the Status Area and go to the Printing Screen when a print is resumed.
• Add extra debugging to help diagnose future diveToFile issues.
• Use "M1000C" instead of recovery.cancel() to send a host notification, etc.

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• A related issue was fixed in Fix diveToFile with open Dir object #19539 where CardReader::diveToFile would fail with an open dir object.