Refactor & deduplicate web UI boot code

[akx]

Describe what this pull request is trying to achieve.

This PR refactors the boot code in webui.py to remove duplication between the initial-boot code and the reload code.

The order in which things get initialized will be slightly changed, but things do seem to Work On My Machine.

It also

• refactors bits and pieces of the boot process to smaller functions
• fixes a typo bug regarding TLS configuration

Additional notes and description of your changes

Each commit should be pretty atomic in itself aside from the final Deduplicate one, which was implemented by way of comparing the initialize() function and the trailing part of the while 1 loop in webui() and harmonizing them statement by statement.

Environment this was tested in

• OS: macOS
• Browser: Chrome
• Graphics card: M2 Max

Test notes:

• generated an image
• reloaded
• generated another image

[AUTOMATIC1111]

It's a very good effort, the duplicated code was a huge eyesore, I'll play around with it and merge it.