Escape key not closing add funds dialog

[jkup]

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Searched for "esc"

Describe the issue you encountered:
Once you open the "Add funds..." dialog on the Payments page you can't close it using just the keyboard. This affects Accessibility and general UI/UX. I see that the dialog component has a listener for it so I'm assuming something else is catching that keyboard event.

Expected behavior:

Hitting escape should close a dialog modal.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  macOS
• Brave Version:
  0.12.0
• Steps to reproduce:
  1. Go to preferences > payments
  2. Click on "Add Funds..."
  3. Hit the escape key
• Screenshot if needed:
• Any related issues:

[bsclifton]

This was attempted with #6248 but had some issues (milestone removed).

If you wanted to try the patch from that PR, you can grab it here:
https://patch-diff.githubusercontent.com/raw/brave/browser-laptop/pull/6248.patch

[ghost]

To retest after refactor of #11037

[srirambv]

Verified on Windows x64

• 0.22.700 9306021
• libchromiumcontent 66.0.3359.139
• muon: 6.0.7

Verified on macOS 10.13.3 x64 using the following build:

• 0.22.706 e11b027
• libchromiumcontent: 66.0.3359.139
• muon: 6.0.9

Verified on Ubuntu 17.10 x64

• 0.22.706 e11b027
• libchromiumcontent 66.0.3359.139
• muon: 6.0.9