Enhance Mistral Conversation Api Component to make the endpoint configurable

[fabistb]

Describe the feature

3rd party services like Azure AI Foundry allow to use Mistral models but have a custom endpoint.
With the current setup it isn't possible to use a custom endpoint and utilize these 3rd party services.

Metadata

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: mistral
spec:
  type: conversation.mistral
  metadata:
  - name: key
    value: mykey
  - name: model
    value: open-mistral-7b
  - name: cacheTTL
    value: 10m
  - name: endpoint
    value: 'https://example.com'

Release Note

RELEASE NOTE: ADD Mistral endpoint configurability