add support to click specified coordinates relavte to an element

[skiloop]

• [x] this is a alternative solution to #191
• [x] Make sure all of the significant new logic is covered by tests
• [x] Rebase your changes on master so that they can be merged easily
• [x] Make sure all tests and linter rules pass
• [x] If you've changed APIs, update the documentation in README and /api/README

[codecov-io]

Codecov Report

Merging #426 into master will decrease coverage by 0.13%. The diff coverage is 30%.

@@            Coverage Diff             @@
##           master     #426      +/-   ##
==========================================
- Coverage   38.03%   37.89%   -0.14%     
==========================================
  Files           7        7              
  Lines         844      847       +3     
  Branches      116      118       +2     
==========================================
  Hits          321      321              
- Misses        523      526       +3

Impacted Files	Coverage Δ
src/util.ts	40.97% <25%> (-0.47%)	:arrow_down:
src/chrome/local-runtime.ts	26.43% <25%> (ø)	:arrow_up:
src/api.ts	47.71% <50%> (ø)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update f172e64...0c4eedb. Read the comment docs.