feat: in-memory state store components

[seeflood]

What this PR does:
Add an in-memory state store component;
Modify wasm documents;

Which issue(s) this PR fixes:

See #67 (comment)

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov]

Codecov Report

Merging #327 (2d7c145) into main (874f546) will not change coverage.
The diff coverage is n/a.

❗ Current head 2d7c145 differs from pull request most recent head 797212d. Consider uploading reports for the commit 797212d to get more accurate results

@@           Coverage Diff           @@
##             main     #327   +/-   ##
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  Coverage   56.90%   56.90%           
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  Files          48       48           
  Lines        2100     2100           
=======================================
  Hits         1195     1195           
  Misses        774      774           
  Partials      131      131           

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