Update state doc 34905

[rakeshcusat]

Issue link: https://github.com/apache/beam/issues/34905

Updated Python State Doc to provide more clarity.

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[rakeshcusat]

@damccorm Were you thinking something similar?

There are a couple of more changes which I am going to add:

1. Update programming doc for missing state(s).
2. Add section in programming doc for utility function such as passing window, timer and other parameter in the timer callback function.

let me know if you have something else in mind as well.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 56.46%. Comparing base (d427d37) to head (c312d9e). Report is 184 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #35209      +/-   ##
============================================
- Coverage     56.49%   56.46%   -0.04%     
  Complexity     3301     3301              
============================================
  Files          1182     1189       +7     
  Lines        181610   182012     +402     
  Branches       3409     3409              
============================================
+ Hits         102599   102771     +172     
- Misses        75740    75970     +230     
  Partials       3271     3271              

Flag	Coverage Δ
python	80.91% <100.00%> (-0.21%)	:arrow_down:

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[tvalentyn]

also ptal at formatter & linter errors. thanks!

[rakeshcusat]

Run Python_Runners PreCommit 3.9

[rakeshcusat]

Run PythonDocs PreCommit

[rakeshcusat]

Run Prism_Python PreCommit 3.9