feat(Area): add readonly prop

[chenjiahan]

#7070

[codecov-commenter]

Codecov Report

Merging #7106 into dev will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #7106   +/-   ##
=======================================
  Coverage   91.31%   91.31%           
=======================================
  Files         177      177           
  Lines        4757     4757           
  Branches      284      284           
=======================================
  Hits         4344     4344           
  Misses        377      377           
  Partials       36       36           

Impacted Files	Coverage Δ
src/area/index.js	90.90% <ø> (ø)

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