Adding negative prompts to Loras in extra networks

[Learwin]

Description

This pull request adds the ability to specify a negative prompt with weight that will be added alongside the prompt to their respective texbox, when clicking a lora card in the extra networks tab. If nothing is specified no additional text will be added to the negative prompts.

To achieve this I modified ui_edit_user_metadata.py, ui_extra_networks_lora.py and ui_extra_networks.py to incorporate these two new fields. I also had to modify extraNetworks.js to allow the prompt and negative prompt to be added at the same time. Additionally I had to add additional regex expressions to match the negative prompt that gets added by clicking on the card.
The two new fields are saved into the models json file.

Screenshots/videos:

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests

[AUTOMATIC1111]

1. I don't think the slider is needed; user can put (:0.7) into his text himself if he needs that.
2. Is this functionality even needed? Are there loras that recommend negative prompt?
3. Does the implementation interfer with the normal functionality of textual inversion tab where you can cloose what prompt tp add text to, by just selecting that prompt?

[Learwin]

1. Yeah the slider is suboptimal, I agree. I can remove if you want.
2. While not extremely common I've definitely come across a few loras that suggested using certain negative prompts.
3. No it does not interfere. Textual inversion prompt will still be added to the active textarea. I've tried to make sure that every existing functionality was kept the same.

[AUTOMATIC1111]

All right, remove the slider and let's get it in.

[Learwin]

Removed the slider and also removed the changes to an unrelated file that must have been changed while I used the python linter.