TypeScript: update grammar and fixes

Summary:
TypeScript:

• Add asserts: https://github.com/microsoft/TypeScript/pull/32695
• Highlight types after as expression.
• Add type helpers: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-5.html#the-omit-helper-type

TypeScript React (TSX):

• When <T extends is detected, highlight as a type assertion, not as a Tag. See: https://github.com/microsoft/TypeScript-TmLanguage/commit/11b1a4f8dc3a3eaa4df71e8cc1ad6f01a688961d

JavaScript React (JSX):

• Use non-capture groups in RegExpr rules.

Reviewers: Framework: Syntax Highlighting, dhaumann, cullmann

Reviewed By: Framework: Syntax Highlighting, cullmann

Subscribers: kwrite-devel, kde-frameworks-devel

Tags: Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D24355