Add support for Python3.10

[seandstewart]

This is an attempt to add support for Python 3.10.

There were quite a few changes to typing runtime and internals that had cascading effects on typical:

• builtins have empty __annotations__.
• TypedDict, NamedTuple are functions, not classes.
• The new Union operator is a completely new type types.Union and is not the same as typing.Union.

Additionally:

• dataclasses got a few shiny updates (kw_only, match_args, slots)
• Pandas can't be installed on python 3.10

Resolves #162

[codecov[bot]]

Codecov Report

Merging #163 (06719bd) into main (34c9f57) will increase coverage by 3.16%. The diff coverage is 96.42%.

@@            Coverage Diff             @@
##             main     #163      +/-   ##
==========================================
+ Coverage   91.88%   95.04%   +3.16%     
==========================================
  Files          37       37              
  Lines        3868     3998     +130     
  Branches      554      557       +3     
==========================================
+ Hits         3554     3800     +246     
+ Misses        241      125     -116     
  Partials       73       73              

Flag	Coverage Δ
3.9	?
unittests	94.92% <87.50%> (+3.04%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
typic/util.py	88.69% <91.66%> (+2.57%)	:arrow_up:
typic/checks.py	97.90% <100.00%> (+0.04%)	:arrow_up:
typic/compat.py	100.00% <100.00%> (ø)
typic/constraints/factory.py	98.19% <100.00%> (ø)
typic/ext/schema/schema.py	98.90% <100.00%> (+0.54%)	:arrow_up:
typic/klass.py	100.00% <100.00%> (ø)
typic/serde/des.py	93.76% <100.00%> (-1.00%)	:arrow_down:
typic/types/dsn.py	100.00% <0.00%> (ø)
typic/types/email.py	100.00% <0.00%> (ø)
... and 15 more

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