Allow variable tags to contain malformed xml

[ang-zeyu]

What is the purpose of this pull request? (put "X" next to an item, remove the rest)

• [x] Bug fix

Fixes the first point mentioned here #1168 (comment)

What is the rationale for this request?
Simple patch to allow <variable> tags to hold any content built on #1047

Is there anything you'd like reviewers to focus on?
na

Testing instructions:
npm run test should pass

Proposed commit message: (wrap lines at 72 characters)
Allow variable tags to contain malformed xml

With the special tags patch, variables are able to contain custom
content possibly containing malformed xml.

Let’s add variable to the list of special tags to do so.

[nbriannl]

Thanks for this fix. Would anything regress now that variables can contain malformed xml? I don't see any reason why anything would regress. Test seem fine, update tests seem ok too.

[marvinchin]

LGTM

[ang-zeyu]

Thanks for this fix. Would anything regress now that variables can contain malformed xml? I don't see any reason why anything would regress. Test seem fine, update tests seem ok too.

Yup, 2103 site had no diffs either. If anything it should fix edge cases of variables currently in use that had slightly incompatible syntax

[damithc]

@ang-zeyu should we update the user guide somewhere to reflect this enhancement?

[ang-zeyu]

@ang-zeyu should we update the user guide somewhere to reflect this enhancement?

Will do, didn't notice this limitation was documented

[damithc]

Tested in production. Good work @ang-zeyu and reviewers.