Apply BrowserButton to clipboardButton

[luixxiul]

• by applying the modified BEM style to dedupe properties
• by replacing span with browserButton
• by setting clipboard fa icon by default

Closes #11373

Auditors:

Test Plan:

1. Open about:brave
2. Click the clipboard button
3. Make sure the data is copied

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.

Test Plan:

Reviewer Checklist:

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[codecov-io]

Codecov Report

Merging #11374 into master will decrease coverage by 0.65%.
The diff coverage is 37.5%.

@@            Coverage Diff             @@
##           master   #11374      +/-   ##
==========================================
- Coverage   52.67%   52.01%   -0.66%     
==========================================
  Files         269      269              
  Lines       25602    25537      -65     
  Branches     4085     4070      -15     
==========================================
- Hits        13485    13284     -201     
- Misses      12117    12253     +136

Flag	Coverage Δ
#unittest	52.01% <37.5%> (-0.66%)	⬇️

Impacted Files	Coverage Δ
...ment/addFundsDialog/steps/addFundsWizardAddress.js	31.25% <ø> (-1.06%)	⬇️
app/renderer/components/common/clipboardButton.js	40% <37.5%> (+4.51%)	⬆️
app/common/state/ledgerState.js	45.56% <0%> (-12.1%)	⬇️
app/browser/api/ledger.js	30.83% <0%> (-8.33%)	⬇️
js/actions/appActions.js	16.51% <0%> (-1.81%)	⬇️
js/constants/windowConstants.js	100% <0%> (ø)	⬆️
app/browser/tabs.js	25.82% <0%> (ø)	⬆️
js/actions/windowActions.js	4.9% <0%> (+0.04%)	⬆️
js/stores/windowStore.js	27.58% <0%> (+0.56%)	⬆️
... and 1 more

[cezaraugusto]

blocking for now as this affects add funds on 0.19.x

[cezaraugusto]

one thing is that with this move we lost the pointer as the cursor. Could make a workaround for this? otherwise this lgtm

[luixxiul]

That will be taken care of https://github.com/brave/browser-laptop/pull/10951/files#diff-0ff973318abdc5c07f55cefe86bd5ed7R110 of #10951. Is it OK to wait until that?

[cezaraugusto]

++