Disable implicit context when opening chat from CLI

[bhavyaus]

Testing #252992

Repro:

1. Open a workspace
2. Have a file A open in the editor
3. Invoke code chat with -a on an unrelated file B and ask it to explain
4. 🐛 File A gets included as an attachment and led to an incorrect chat response.

[bpasero]

@roblourens this needs some kind of support for me to disable the implicit context widget when I open the chat view, is there a way?

@justschen do you know maybe?

[roblourens]

You should be able to get the implicit context from here

vscode/src/vs/workbench/contrib/chat/browser/chatInputPart.ts

Line 192 in 03394e2

public get implicitContext(): ChatImplicitContext | undefined {

and .enabled = false. Or, we could add a flag to workbench.action.chat.open maybe

[bpasero]

@roblourens yeah going down that path means it is disabled and then stays disabled even when I create new chats, so it might backfire.