feat(lint): add variable assignment tracking to noDocumentCookie rule

[tunamaguro]

Summary

This is followup PR to #4204 .

This PR extends the implementation of noDocumentCookie by adding support for tracking assignments to variables.

Now, the following code will be supported.

const doc = document;
doc.cookie = "foo = bar";

Test Plan

• Added tests to verify the handling of variable assignments.

[codspeed-hq]

CodSpeed Performance Report

Merging #4255 will not alter performance

_{Comparing tunamaguro:track-document-assign (c1debf8) with main (fbe5552)}

Summary

✅ 105 untouched benchmarks

[ematipico]

Awesome work @tunamaguro!