Added StrictBytes type

[rlizzo]

Change Summary

Added StrictBytes type which rejects objects which are castable to bytes (ie. int, float, str), but which are not natively bytes type. All changes are modeled after StrictStr, StrictInt, StrictFloat, and StrictBool types.

• Added strict option to ConstrainedBytes class. Default value of the option (False) respects downstream code continuity. Any initialization or subclass of ConstrianedBytes behaves identically to prior implementations unless the "strict" option is explicitly set to True).

• Added strict_bytes_validator which rejects any object which is not Union[bytes, bytearray] type. Because bytearray instances are just mutable versions of bytes, we accept both as equivalent native byte types. This is noted explicitly since the builtin bytearray construtor creates objects with the following behavior:

>>> isinstance(bytearray('foo', 'utf-8'), bytes)
False

Related issue number

n/a

Checklist

• Unit tests for the changes exist
• Tests pass on CI and coverage remains at 100%
• Documentation reflects the changes where applicable
• changes/<pull request or issue id>-<github username>.md file added describing change
  (see changes/README.md for details)

[rlizzo]

cc @hhsecond

[codecov]

Codecov Report

Merging #2136 (a871ae1) into master (31bc243) will decrease coverage by 0.36%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##            master    #2136      +/-   ##
===========================================
- Coverage   100.00%   99.63%   -0.37%     
===========================================
  Files           21       21              
  Lines         4093     4121      +28     
  Branches       823      829       +6     
===========================================
+ Hits          4093     4106      +13     
- Misses           0       12      +12     
- Partials         0        3       +3     

Impacted Files	Coverage Δ
pydantic/types.py	100.00% <100.00%> (ø)
pydantic/validators.py	100.00% <100.00%> (ø)
pydantic/version.py	88.23% <0.00%> (-11.77%)	⬇️
pydantic/typing.py	94.30% <0.00%> (-5.70%)	⬇️
pydantic/env_settings.py	97.93% <0.00%> (-2.07%)	⬇️
pydantic/networks.py	99.22% <0.00%> (-0.78%)	⬇️
pydantic/utils.py	99.29% <0.00%> (-0.71%)	⬇️
pydantic/json.py	100.00% <0.00%> (ø)
pydantic/fields.py	100.00% <0.00%> (ø)
... and 2 more

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[samuelcolvin]

LGTM, @PrettyWood are you happy with this? If so feel free to merge.

[rlizzo]

Thanks for the review @samuelcolvin and @PrettyWood!