Add bookmarklet support

[andreiburov]

Description:

Like mentioned in the previous repo, there is a need for the bookmarklet support https://github.com/brave/browser-ios/issues/1724. Thus feature is supported by both safari and firefox on ios.

[srirambv]

Verification passed on iPad Pro with iOS 13.2 running 1.13(19.10.16.18)

• Verified bookmark can't be saved with just

javascript:function() {}

• Verified bookmark can't be saved with just

javascript:

• Verified bookmark is saved as below but doesn't show any error when loading

javascript:fun

• Verified bookmark can be saved as below and an alert prompt is shown

javascript:(function(){ alert("hello"); })()

• Verified editing an existing bookmark to https://brave.com successfully updates the favicon and loads the site when selected
• Logged Bookmarklet on newtab shows title as localhost:6571 #1724 for alert box title being localhost

[srirambv]

Verification passed on iPad Pro with iOS 12.4 running 1.13(19.10.16.18)

• Verified bookmark can't be saved with just

javascript:function() {}

• Verified bookmark can't be saved with just

javascript:

• Verified bookmark is saved as below but doesn't show any error when loading

javascript:fun

• Verified bookmark can be saved as below and an alert prompt is shown

javascript:(function(){ alert("hello"); })()

[srirambv]

Verification passed on iPhone Xr with iOS 13.2 running 1.13(19.10.18.15)

• Verified bookmark can't be saved with just

javascript:function() {}

• Verified bookmark can't be saved with just

javascript:

• Verified bookmark is saved as below but doesn't show any error when loading

javascript:fun

• Verified bookmark can be saved as below and an alert prompt is shown

javascript:(function(){ alert("hello"); })()

Verification passed on iPhone 7+ with iOS 13.2 running 1.13(19.10.18.15)

• Verified bookmark can't be saved with just

javascript:function() {}

• Verified bookmark can't be saved with just

javascript:

• Verified bookmark is saved as below but doesn't show any error when loading

javascript:fun

• Verified bookmark can be saved as below and an alert prompt is shown

javascript:(function(){ alert("hello"); })()

Verification passed on iPhone 6 with iOS 12.4 running 1.13(19.10.18.15)

• Verified bookmark can't be saved with just

javascript:function() {}

• Verified bookmark can't be saved with just

javascript:

• Verified bookmark is saved as below but doesn't show any error when loading

javascript:fun

• Verified bookmark can be saved as below and an alert prompt is shown

javascript:(function(){ alert("hello"); })()

[micahjon]

Has anyone figured out how to install the Push to Kindle bookmarklet on Brave? Works fine in Safari, but evidently fails validation in Brave. Would be nice if there was some error message or something
https://www.fivefilters.org/push-to-kindle/push-to-kindle-bookmarklet/