Syntax highlighting and brace matching for "switch/when" statements

[robcowell]

Summary

Syntax highlighting and brace matching doesn't correctly parse switch/when clauses

Steps To Reproduce:

1. Write a switch on/when structure as per screenshot.

Expected result

1. Strings in when clause should be consistently syntax highlighted
2. Bracket matching should match up pairs

Actual result

1. Odd colouring from the syntax highlighting
2. Need to put a trailing space between end of when clause and opening brace { even when the brace is on a new line or the brace pairs aren't matched both in syntax and on save/deploy

Additional information

VS Code Version: 1.44.2

Theme: Codey Midnight by @zaynelt

SFDX CLI Version: sfdx-cli/7.53.0-839fc82926 win32-x64 node-v10.15.3

OS and version: Win 10 x64 1909 build 18363.778