chore: Update create-vsix to support multi-vsix and shared bot logic

[TwitchBronBron]

Summary

• Adds a new create-vsix workflow (this repo didn't have one before) so PRs can be labeled create-vsix to trigger a vscode-brightscript-language vsix build that includes this branch's changes
• Includes a workflow_dispatch trigger (with a pr input accepting a PR number or full URL) so this can be tested without needing a labeled PR
• Forwards branch, pr, and repo to vscode-brightscript-language's create-vsix workflow, which builds the .vsix files and posts the download-links comment directly on the originating PR
• Requires logger to be wired into vscode-brightscript-language's create-vsix.ts build graph (see chore: Update create-vsix to support multi-vsix and shared bot logic vscode-brightscript-language#847) for a logger PR's changes to actually be reflected in the built vsix

[rokucommunity-bot]

Hey there! I just built a new version of the vscode extension based on f306d8b.

Download:

• brightscript (replaces store version)
• brightscript-temp (side-by-side install)

Install instructions.