clear stale states when creating new one

[pamapa]

This fixes the case when clearStaleState is never called in user code. Sooner or later window.localStorage is full and adding an additional state results in a QuoteExceededError.

Closes/fixes #466

Checklist

• This PR makes changes to the public API
• I have included links for closing relevant issue numbers

[codecov]

Codecov Report

Merging #511 (1b39579) into main (7a6a20c) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #511      +/-   ##
==========================================
+ Coverage   75.17%   75.20%   +0.03%     
==========================================
  Files          44       44              
  Lines        1575     1577       +2     
  Branches      290      290              
==========================================
+ Hits         1184     1186       +2     
  Misses        364      364              
  Partials       27       27              

Flag	Coverage Δ
unittests	75.20% <100.00%> (+0.03%)	⬆️

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

Impacted Files	Coverage Δ
src/OidcClient.ts	94.33% <100.00%> (+0.10%)	⬆️

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[pamapa]

@kherock Time to review this?

[pamapa]

@kherock would be nice if you have time to review this one...

[kherock]

sorry for the delay! This looks good to me.