Optimise Tauri builds (#5404)

# Description of Changes
- Just build proper installers in CI for each platform
- Provide commands to build just the bundled apps without the need for
installers locally
  - `tauri-dev` - Builds quickly for an unoptimised version of the app
  - `tauri-build` - Builds the full optimised app installer for release
- `tauri-build-dev` - Builds an optimised app with no bundling (builds
to a folder on Mac; raw `.exe` on Windows; etc.)
- `tauri-build-dev-mac` - Builds an optimised bundled Mac app with no
installer (as an `.app` file)
- `tauri-build-dev-windows` - Builds an optimised bundled Windows app as
an `.nsis` installer
- `tauri-build-dev-linux` - Builds an optimised bundled Linux app as an
`.appimage`

frontend/src-tauri/tauri.conf.json

@@ -26,7 +26,6 @@
             "deb",
             "rpm",
             "dmg",
-            "app",
             "msi"
         ],
         "icon": [