PFW-1294: Don't attempt to find SD file when recovering USB print

[gudnimg]

Summary of changes:

• Remote host prints (serial and USB): there is no filename on the printer side (in RAM or EEPROM). Power panic recovery for remote prints should not attempt to recover a filename from the printer and interact with the SD card (which may not even be connected)
• SD print: The filename recovery is split into a separate function. This will be useful later to optimise code size in "Reprint" LCD menu. (PFW-1536)
• SD print: Support any valid DOS 8.3 filename. Previously .gco extension was hardcoded, but now .g will work as well. A new EEPROM entry is added EEPROM_FILENAME_EXTENSION
• SD print: Generally refactor reading and writing the filename & directory.
  • Write/read EEPROM blocks instead of one byte at a time.
  • Don't convert the SFN to lower case. The code that searches for the matching filename is not case sensitive.

TODO:

• Test very short filename e.g. "test.gcode" (Starting a print, Power panic, and Power panic recovery)
• Do some more testing and try to break things :)

[github-actions]

All values in bytes. Δ Delta to base

Target	ΔFlash	ΔSRAM	Used Flash	Used SRAM	Free Flash	Free SRAM
MK3S_MULTILANG	-70	-4	245962	5634	7990	2558
MK3_MULTILANG	-68	-4	245250	5643	8702	2549

[gudnimg]

Notes on testing changes to short filename (card.filename) on Windows. Use this command in Powershell to see the short filenames on the SD card cmd /c dir /x

https://devblogs.microsoft.com/scripting/use-powershell-to-display-short-file-and-folder-names/

This is my SD card setup (tree d:\ /f):

D:\
│   Shape-Box_0.4n_0.2mm_PETG_MK3SMMU2S_39m.gcode
│   findarunout.gcode
│   3dbenchy_0.6n_0.2mm_PLA_MK3SMMU2S_1h10m.gcode
│   Shape-Box_0.6n_0.2mm_PLA_MK3SMMU3_1h50m.gcode
│   t.gcode
│   te.gcode
│   test.gcode
│   tes.gcode
│   testt.gcode
│   testte.gcode
│   testtes.gcode
│   testtest.gcode
│
├───te
│       t.gcode
│       te.gcode
│       tes.gcode
│       test.gcode
│       testt.gcode
│       testte.gcode
│       testtes.gcode
│       testtest.gcode
│
└───testfolder
        t.gcode
        te.gcode
        tes.gcode
        test.gcode
        testt.gcode
        testte.gcode
        testtes.gcode
        testtest.gcode

[3d-gussner]

Tested on MK404

• SD print works as known.