Add watermark for input box (#4117)

[rchiodo]

• Add watermark for input box

• Add news entry

• Fix hygiene after merge

For #

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Has a news entry file (remember to thank yourself!)
• Has sufficient logging.
• Has telemetry for enhancements.
• Unit tests & system/integration tests are added/updated
• Test plan is updated as appropriate
• package-lock.json has been regenerated by running npm install (if dependencies have changed)

[codecov]

Codecov Report

Merging #4124 into release will increase coverage by 1%.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           release   #4124   +/-   ##
=======================================
+ Coverage       79%     79%   +1%     
=======================================
  Files          407     407           
  Lines        18645   18646    +1     
  Branches      3007    3007           
=======================================
+ Hits         14609   14615    +6     
+ Misses        4033    4028    -5     
  Partials         3       3

Flag	Coverage Δ
#Linux	68% <100%> (ø)	⬇️
#Windows	68% <100%> (+1%)	⬆️
#macOS	68% <100%> (+1%)	⬆️