Replace Python-based CRC methods with C++ variants

[kerel-fs]

gr-satellites provides a C++ implementation of generic CRCs in (satellites/crc.h). Starting with GNU Radio 3.10, this got upstreamed in gr-digital (gr-digital/include/gnuradio/digital/crc.h).

At the same time, there are multiple Python-based implementations that could be deprecated and replaced with using the C++ implementation, eg. check_eseo_crc.crc16_ccitt_zero:

gr-satellites/python/check_eseo_crc.py

Lines 51 to 58 in 07a0cbd

	def crc16_ccitt_zero(data):
	crc = 0
	for byte in data:
	tbl_idx = ((crc >> 8) ^ byte) & 0xff
	crc = (crc_table[tbl_idx] ^ (crc << 8)) & 0xffff
	return crc & 0xffff

As recently described, this can be replaced with something like

from . import crc
crc_function = crc(16, 0x1021, 0xffff, 0x0, False, False)

# ....
crc_function.compute(...)

(Non-exhaustive) list of Python-based CRC implementations in gr-satellites

• check_eseo_crc.crc16_ccitt_zero
• check_cc11xx_crc.crc16
• check_tt64_crc.crc16_arc
• check_crc16_ccitt_false.crc16_ccitt_false

Note that the underlying blocks themself are deprecated, replaced by the crc_check block. So maybe they should not be modified but replaced instead?