[refactor] Create `src/web/` and abstract related logic

[pnc-nz]

webserver.py would be better split into a folder where we can break out the logic into routes/middleware/etc.

For example, a tree of this might look like:

├── **web**/
 │   ├── ___init__.py_
 │   ├── _server.py_  
 │   ├── **routes**/
 │    │   ├── ___init__.py_
 │    │   ├── _auth.py_           
 │    │   ├── _applications.py_   
 │    │   ├── _panels.py_         
 │    │   └── _positions.py_      
 │   ├── **middleware**/
 │    │   ├── ___init__.py_
 │    │   ├── _auth.py_      
 │   ├── **utils**/
 │    │   ├── ___init__.py_
 │    │   ├── _templates.py_      
 │    │   ├── _validators.py_