DRIVERS-3123 add test skip and clarification

[kevinAlbs]

Follow-up to #1812. Applies pending suggestions from review:

• Allow drivers to skip the comparison test if the Vector type does not support comparison. The C driver's bson_vector_packed_bit_view_t does not support comparison.

• Do not use Binary.from_vector in test example with non-zero ignored bits. PyMongo 4.14.0-dev raises an exception:

>>> b2 = Binary.from_vector([0b11111111], BinaryVectorDtype.PACKED_BIT, padding=7)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/kevin.albertson/code/mongo-python-driver/bson/binary.py", line 482, in from_vector
    raise ValueError(
ValueError: Vector has a padding P, but bits in the final byte lower than P are non-zero. They must be zero.

Please complete the following before merging:

• [ ] Update changelog.
• [ ] Test changes in at least one language driver.
• [ ] Test these changes against all server versions and topologies (including standalone, replica set, and sharded
  clusters).

[caseyclements]

I like this. Thank you for catching the oversight! I'd still like the example of equality though.

assert b1 == Binary.from_vector([0b10000000], BinaryVectorDtype.PACKED_BIT, padding=7)

[kevinAlbs]

I added another value with the same data representation as b1 to add equality comparisons.

While here, I also realized it may not be reasonable to assume every driver may support constructing a Vector type with non-zero ignored bits. I added another condition to skip this test.

[kevinAlbs]

Discussed offline. Used the form b3 = Binary.from_vector([0b10000000], BinaryVectorDtype.PACKED_BIT, padding=7) to express the data in the base-literal notation.

[caseyclements]

LGTM.

[JamesKovacs]

LGTM