Add some tests and raw patch support

[esyr-rh]

The first part of the patch set is focused on adding some minimal testing infrastructure that checks against existing microcode container files and some synthetic tests to check various parser core cases. The second one expands on abilities to work with raw patches, which makes sense for fam 17h+ patches, as their CPUID can be reconstructed from the patch level, as Linux does already[1]; with the introduction of the --generate-missing-equivalence-table-entries, it is now possible to do the following:

$ ./amd_ucode_info.py --generate-missing-equivalence-table-entries -m microcode_amd_fam1ah.bin  ../CPUMicrocodes/AMD/cpu00B*.bin
Microcode patches in ../CPUMicrocodes/AMD/cpu00B20F40_ver0B204011_2024-04-16_AD27994B.bin:                                   
  Family=0x1a Model=0x24 Stepping=0x00: Patch=0x0b204011 Length=14368 bytes
Microcode patches in ../CPUMicrocodes/AMD/cpu00B40F00_ver0B400034_2024-03-18_5476AE6A.bin:
  Family=0x1a Model=0x40 Stepping=0x00: Patch=0x0b400034 Length=14368 bytes
Microcode patches in ../CPUMicrocodes/AMD/cpu00B40F40_ver0B40401A_2024-06-14_544DFCB8.bin:
  Family=0x1a Model=0x44 Stepping=0x00: Patch=0x0b40401a Length=14368 bytes
../CPUMicrocodes/AMD/cpu00B20F40_ver0B204011_2024-04-16_AD27994B.bin+0x0000: WARNING: Generating missing equivalence table item in microcode_amd_fam1ah.bin with CPUID 0x00b20f40 (Family=0x1a Model=0x24 Stepping=0x00) for patch ID 0x0b204011, equivalence ID 0xb240
../CPUMicrocodes/AMD/cpu00B40F00_ver0B400034_2024-03-18_5476AE6A.bin+0x0000: WARNING: Generating missing equivalence table item in microcode_amd_fam1ah.bin with CPUID 0x00b40f00 (Family=0x1a Model=0x40 Stepping=0x00) for patch ID 0x0b400034, equivalence ID 0xb400
../CPUMicrocodes/AMD/cpu00B40F40_ver0B40401A_2024-06-14_544DFCB8.bin+0x0000: WARNING: Generating missing equivalence table item in microcode_amd_fam1ah.bin with CPUID 0x00b40f40 (Family=0x1a Model=0x44 Stepping=0x00) for patch ID 0x0b40401a, equivalence ID 0xb440
Microcode written to microcode_amd_fam1ah.bin
$  ./amd_ucode_info.py -v microcode_amd_fam1ah.bin
Microcode patches in microcode_amd_fam1ah.bin:
  Family=0x1a Model=0x24 Stepping=0x00: Patch=0x0b204011 Length=14368 bytes Start=84 bytes Date=2024-04-16 Equiv_id=0xb240
  Family=0x1a Model=0x40 Stepping=0x00: Patch=0x0b400034 Length=14368 bytes Start=14460 bytes Date=2024-03-18 Equiv_id=0xb400
  Family=0x1a Model=0x44 Stepping=0x00: Patch=0x0b40401a Length=14368 bytes Start=28836 bytes Date=2024-06-14 Equiv_id=0xb440

, thusly filling the gap in missing family 1Ah microcode updates in the linux-firmware repository, based on publicly available ones.

Still missing:

• Unit tests for some specific functions
• Tests for merge functionality
• Tests for raw patch parsing

Note: test_published.py implements some downloading and caching of missing published microcode containers in order to avoid having those in the repository itself due to their license.

The series depends on [2] and starts with various minor changes and cleanups before introducing the tests themselves, to avoid the noise of updating the expected output after introducing those.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=94838d230a6c835c
[2] #2