ci: clean up output, use xxd when dumping binaries

[igrr]

• place binutils and micropython builds into folds
• split test scripts into unit tests and compatibility tests
• make compatibility test output less noisy when tests pass
• use xxd -e instead of hexdump to display binaries in groups of 4 bytes, little-endian format.

Example of a passing test:

$ ./01_compat_tests.sh Testing compat/alu.S	Building using py-esp32-ulp	Building using binutils	Build outputs match 

Example of a failing test:

$ ./01_compat_tests.sh Testing compat/alu.S	Building using py-esp32-ulp	Building using binutils	Build outputs differ! Compatibility test failed for compat/alu.S py-esp32-ulp log: Symbols: text section: 70400039 724ffff3 724a5a55 70600039 726ffff3 726a5a55 7207fff5 7208000c 720ffff3 72000016 7227fff5 7228000c 722ffff3 72200016 50000005 size: 60 data section: size: 0 bss section: size: 0 py-esp32-ulp output: 00000000: 00706c75 003c000c 00000000 70400039 ulp...<.....9.@p 00000010: 724ffff3 724a5a55 70600039 726ffff3 ..OrUZJr9.`p..or 00000020: 726a5a55 7207fff5 7208000c 720ffff3 UZjr...r...r...r 00000030: 72000016 7227fff5 7228000c 722ffff3 ...r..'r..(r../r 00000040: 72200016 50000005 .. r...P binutils output: 00000000: 00706c75 003c000c 00000000 70400039 ulp...<.....9.@p 00000010: 724ffff3 724a5a55 70600039 726ffff3 ..OrUZJr9.`p..or 00000020: 726a5a55 7207fff5 7208000c 720ffff3 UZjr...r...r...r 00000030: 72000016 7227fff5 7228000c 722ffff3 ...r..'r..(r../r 00000040: 72200016 50000001 .. r...P 

[ThomasWaldmann]

thanks!