[FEATURE] Don't apply server timeout during form elicitation

# Feature

If a tool triggers a form elicitation, then the tool must wait for the user to complete that elicitation. The user may take longer than the server timeout setting for that server.

The default timeout is 10 seconds, which may not be enough time for the user to fill out the form. We can increase the timeout up to 10 minutes, which is probably fine for most elicitations, but that increases the timeout for all tools, including ones that don't require elicitation and should complete much faster.

# Solution

Disable the server timeout for the active tool call while an elicitation is in progress. Since the responsibility for progress is on the user, I think it's reasonable to let them take as much time as they need. I don't know if it's possible to identify the particular tool call request that is associated with the elicitation. If not, then perhaps disable all tool call timeouts during form elicitation (it is difficult for the user to trigger a new tool call while the modal elicitation dialog is up).