Apply "right" positioning for SuggestionsOverlay

[lucioperca]

Fixes #425 by correctly positioning the suggestions overlay at the right side of the input when appropriate.

• Adds right as a property for SuggestionsOverlay.
• Includes right when destructuring and checking for changes in suggestionsPosition in the MentionsInput component. Passes this value into SuggestionsOverlay.

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/signavio/react-mentions/mous297rc
✅ Preview: https://react-mentions-git-fork-lucioperca-suggestions-right-position.signavio.vercel.app

[codecov-commenter]

Codecov Report

Merging #426 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #426   +/-   ##
=======================================
  Coverage   78.87%   78.87%           
=======================================
  Files          31       31           
  Lines         691      691           
  Branches      107      107           
=======================================
  Hits          545      545           
  Misses        145      145           
  Partials        1        1           

Impacted Files	Coverage Δ
src/SuggestionsOverlay.js	66.00% <ø> (ø)
src/MentionsInput.js	68.75% <100.00%> (ø)

---

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 3e03692...a02ffd0. Read the comment docs.

[lucioperca]

Same issue is fixed by: #661