New functionality to allow reading flash memory and to query chip id/revision

[tjko]

In case you find this useful. This change add additional functionality to CCLoader to also read/dump flash from C254x chips (if flash is not protected) as well as to identify chip and its revision. Read functionality was tested by successfully backing up latest MH-10 firmware from a MH-10 unit.

Usage: ./ccloader_tng <serialport> <device> <command> [<bin file> [<verify> | <read_start_block> <read_blocks>]]
Examples:
Read Chip ID: ./ccloader_tng /dev/ttyUSB0 1 id
 Write Flash: ./ccloader_tng /dev/ttyUSB0 1 write flash.bin 1
  Read Flash: ./ccloader_tng /dev/ttyUSB0 1 read dump.bin 0 512
Example: ./ccloader_tng /dev/ttyUSB0 1 id
          <device>: 0 -- Default (e.g. UNO)
                    1 -- Leonardo/Mini Pro/etc...
          <verify>: 0 -- No verify (default)
                    1 -- Verify (when flashing)
 <read_stat_block>: 0 -- Start flash dump from block (0 = beginning of the flash)
     <read_blocks>: 512 -- How many blocks to read (512 = 256Kb)

Note! This merge request only contains updated Arduino sketch as well as updated Linux command line tool. (Windows/MacOSX tools would need to be updated to work with the enhanced Arduino sketch...)

[AranVink]

Thanks for this, exactly what I was looking for! Thought about implementing this after looking at the code in main but you beat me to it 👍
If it works out for me then I'll create a PR to add the Windows/MacOSX to your PR so it works across all platforms