feat: Windows support

[lost-theory]

What I did

Added Windows support for the Hardhat network provider.

How I did it

See ApeWorX/ape#91 (comment) for steps on installing Ape on Windows. Once I got that to work, all that was needed was a small amount of OS-specific code to manage the Hardhat process on Windows.

How to verify it

No CI support yet (blocked by ApeWorX/ape#91) but the test suite is passing locally for me:

PS C:\Users\orayo\Documents\steve\ape-hardhat> ..\ape-env\Scripts\pytest.exe
=== test session starts ===
platform win32 -- Python 3.8.6, pytest-6.2.5, py-1.10.0, pluggy-0.13.1
rootdir: C:\Users\orayo\Documents\steve\ape-hardhat, configfile: pytest.ini
plugins: hypothesis-6.23.0, cov-2.12.1, forked-1.3.0, xdist-2.4.0, web3-5.23.1
gw0 [17] / gw1 [17] / gw2 [17] / gw3 [17]
................. [100%]
=== warnings summary ===
tests/test_hardhat.py::test_rpc_methods[get_balance-args1-0]
  c:\users\orayo\documents\steve\ape-env\lib\site-packages\web3\method.py:215: DeprecationWarning: getBalance is deprecated in favor of get_balance
    warnings.warn(

tests/test_hardhat.py::test_rpc_methods[get_nonce-args0-0]
  c:\users\orayo\documents\steve\ape-env\lib\site-packages\web3\method.py:215: DeprecationWarning: getTransactionCount is deprecated in favor of get_transaction_count
    warnings.warn(

tests/test_hardhat.py::test_rpc_methods[get_code-args2-]
  c:\users\orayo\documents\steve\ape-env\lib\site-packages\web3\method.py:215: DeprecationWarning: getCode is deprecated in favor of get_code
    warnings.warn(

-- Docs: https://docs.pytest.org/en/stable/warnings.html
=== 17 passed, 3 warnings in 61.00s (0:01:01) ===

Checklist

• Passes all linting checks (pre-commit and CI jobs)
• New test cases have been added and are passing
• Documentation has been updated
• PR title follows Conventional Commit standard (will be automatically included in the changelog)