Update empty consent and persist initial state

[edgarlr]

fixes #19

[edgarlr]

@bring-shrubbery Hey, I added the change we talked about the other day, let me know your thoughts or if you have a different approach in mind and I can update it!

[codecov-commenter]

Codecov Report

Merging #21 (ae53f63) into main (96f125b) will decrease coverage by 1.64%.
The diff coverage is 87.50%.

@@            Coverage Diff             @@
##             main      #21      +/-   ##
==========================================
- Coverage   93.47%   91.83%   -1.65%     
==========================================
  Files           3        3              
  Lines          46       49       +3     
  Branches       14       16       +2     
==========================================
+ Hits           43       45       +2     
- Misses          3        4       +1     

Impacted Files	Coverage Δ
src/useCookieConsent.ts	89.18% <85.71%> (-1.99%)	⬇️
src/constants.ts	100.00% <100.00%> (ø)

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[bring-shrubbery]

Thanks for the PR @edgarlr!

I've released this PR under version v0.3.5