multiple dependent extensions can conflict when setting our extension settings

Whichever extension sets the timeout path, existing dotnet path, and telemetry setting first can win and those values will not be overridden by calling extensions. Per @baronfel we should subscribe to the onConfigurationDidChange notification so we can react to this better. If any extension requests telemetry as false we should just not collect any. We can maximize the timeout value and we can also use a list of dotnet paths instead.

We could provide an option to override this in a context but this seems suboptimal.