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!