Markdown, TypeScript & Logcat: some fixes

Summary:
Markdown:

• Fix Markdown code in fenced code blocks.
• Allow escapes within reference links.

TypeScript:

• Fix: don't highlight operator ? (ex: identifier?: string) as a conditional expression.

Logcat:

• Restore style: turn off attributes in itemData's.

Reviewers: Framework: Syntax Highlighting, dhaumann, cullmann

Reviewed By: Framework: Syntax Highlighting, dhaumann

Subscribers: kwrite-devel, kde-frameworks-devel

Tags: Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D23657