Front-End Architectural Improvements

### Description

_No response_

### Which customers would this be available to

None
```[tasklist]
### Other
- [ ] https://github.com/FlowFuse/flowfuse/issues/4028
- [ ] Webpack: code splitting w/ dynamic imports https://webpack.js.org/guides/code-splitting/
- [ ] Webpack: tree shaking https://webpack.js.org/guides/tree-shaking/
- [ ] Webpack: Hot Module Replacement https://webpack.js.org/concepts/hot-module-replacement/
- [ ] controversial: extracting from forge app (currently serving static assets via fastify server)
```

```[tasklist]
### Separations of concerns
- [ ] #1991
- [ ] https://github.com/FlowFuse/flowfuse/issues/4029
```

```[tasklist]
### Prerequisites
- [ ] Improve e2e test coverage
- [ ] Extract common methods/data/computed props into mixins would allow us to detect repetitive paterns across components and ease our decision if certain data should be persisted in a store
```

```[tasklist]
### Code Cleanup / DX
- [ ] Create and use webpack aliases | Decouple components from namespaces
- [ ] Rethink fontend folder structure: images/data/stylesheets/ui-components/utils firectories
```