refactor(ui): reorganize imports

[Red-Asuka]

This pull request includes several changes across multiple files to improve the structure and organization of imports, update Tailwind CSS configurations, and adjust module exports. The most important changes include refactoring imports, updating Tailwind CSS content paths, and modifying the package.json files for better module resolution.

Refactoring imports:

• apps/desktop/src/renderer/src/App.vue: Separated imports from @mqttx/ui into @mqttx/ui/i18n and @mqttx/ui/stores.
• apps/web/src/App.vue: Similar separation of imports from @mqttx/ui into @mqttx/ui/i18n and @mqttx/ui/stores.
• apps/desktop/src/renderer/src/main.ts and apps/web/src/main.ts: Updated imports and added createPinia for state management.

Updating Tailwind CSS configurations:

• apps/desktop/tailwind.config.ts and apps/web/tailwind.config.ts: Expanded content paths to include files from ../../packages/ui/src. [1] [2]

Modifying package.json files:

• packages/ui/package.json: Added exports field to specify module entry points for better module resolution.
• package.json: Removed the postinstall script for generating UI.

Additional changes:

• packages/ui/src/styles/index.scss: Commented out the @forward for iconfont.css to address a FIXME note.