Update dtk-template & add clangd support

[encounter]

This updates dtk-template with all of the latest changes, including:

• CLI progress output now shows matched code % across all source files, including unlinked.
• Progress badges now use matched code % from decomp.dev rather than linked %.
• Adds vscode config to enable dtk-template's new clangd integration.
• Support automatically extracting required files from the game disc by placing it in orig/GMPE01_00. Setup instructions updated to reflect this.
• CI updated to point to the new build image.

The second commit includes various source changes that fix some errors that appear with clangd. There's still remaining issues to solve: many implicit declarations and invalid function pointer casts, but I'll let y'all handle those.