[py] Add page load strategy enum

[M1troll]

Description

Add PageLoadStrategy to get rid of writing the webdriver's page load strategy manually.

Motivation and Context

Fixes issue#13236:

Hi!

In my project, I've encountered a situation where I need to change the default page load strategy, but the only way to find the names of the available strategies is by searching the documentation or looking at the descriptor implementation.

I think it would be convenient to have an enum for these names. This would help with hints of available strategy names and save us from having to remember their full names. It would also be great to add info about difference between these strategies in the docstring of this class, as is done in the documentation.

Thanks!

Usage example

If enum is named PageLoadStrategy, I can easily use strategy name as follows:

from selenium import webdriver
from selenium.webdriver.chrome.options import Options, PageLoadStrategy

options = Options()
options.page_load_strategy = PageLoadStrategy.EAGER

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation. -> normal, eager, none for Python
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov-commenter]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (6620bce) 57.95% compared to head (03e7bcc) 57.99%.

❗ Current head 03e7bcc differs from pull request most recent head 70bc6c2. Consider uploading reports for the commit 70bc6c2 to get more accurate results

Files	Patch %	Lines
py/selenium/webdriver/common/options.py	83.33%	1 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##            trunk   #13258      +/-   ##
==========================================
+ Coverage   57.95%   57.99%   +0.03%     
==========================================
  Files          88       88              
  Lines        5333     5338       +5     
  Branches      224      224              
==========================================
+ Hits         3091     3096       +5     
  Misses       2018     2018              
  Partials      224      224              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[isaulv]

One concern I have is that enum string objects remain Enums until a json library parses it as a string object. But if tests pass, this is fine.

[diemol]

Thank you, @M1troll!

Thank you for reviewing, @isaulv!

[titusfortner]

@isaulv do you have specific code recommendation for that?

[isaulv]

@titusfortner the enum object is fine so long it gets ran through a JSON converter. If it doesn't, and that caps object is used in some other context it may not work right.