Gemini URL Context Support

[rickwestrate]

https://ai.google.dev/gemini-api/docs/url-context
Would be fantastic to support Gemini's feature of fetching context from any pasted url. This could help greatly when struggling over the exact syntax of something where the answer clearly resides on a documentation page whos url could be pasted. Even better when combined with grounding with google search so the model can do a google search, and then answer questions against a specific url. Powerful stuff that *could vastly improve the experience in Roo when using the Gemini models.