feat: Extension should be able to register its own settings

[louis-jan]

Problem

• Extension now could not able to register settings. New inference extensions require credentials to work with endpoints.

Success Criteria

• From a extension class

  
  interface OAISettings {
  key?: string | undefined
  }

const DEFAULT_SETTINGS: Partial = { key: "xxx-yyyy", };

class OAIExtension extends JanExtension { settings: OAISettings

onLoad() { this.settings = Object.assign({}, DEFAULT_SETTINGS, await this.loadData()); } }

**Additional context**
User should be able to update settings from setting page > extensions > oai extension > settings

Base Extension class should have a default implementation of 
```ts
// Read extension data from json file 
function loadData()

// Write extension data to json file
function saveData(data: object)

Q: Web & Mobile compatibility? A: inject localStorage module (session based) instead of fs for these platforms

Further update

• Settings can be updated via registered commands / setting tabs (UIFramework constraint)

[dan-homebrew]

Thanks - I think this will be a great way to start work on https://github.com/janhq/jan/issues/757

[imtuyethan]

Design for dynamic extension settings: https://www.figma.com/file/ytn1nRZ17FUmJHTlhmZB9f/Jan-App-(version-1)?type=design&node-id=6999-89915&mode=design&t=IhyPYt0bZS0kM65Y-4

[Van-QA]

1. Extension group name should be in upper case for all text :x:, see Figma design above

2. Inconsistent in the hyperlink text: Groq Documentation and OpenAI documentation :x:

   

[Van-QA]

3. API key placeholder should contain prefix of the sample key :x:
   • openAI: sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
   • Groq: gsk_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

[Van-QA]

looking good on Jan v0.4.10-367 ✅