chore: improve dev docker for offline + other fixes

[NGPixel]

Docker Changes

• change docker-compose end behavior from down to stop
• set workspace directory to /workspace instead of /root/src to address issues mentioned by @jennifer-richards

NPM Changes

• pre-install npm modules during image build
• add --prefer-offline flag to npm install during container start
• disable the npm funding and auditing messages during init install

VS Code Changes

• make the wait-for script available offline instead of fetching it during vscode container start
• add gitlens, indent-rainbow and volar extensions to the default vscode config