Showing message in tachometer about ipykernel's required version

[pinksi]

Problem

To show the kernel usage in the sidebar after clicking the tachometer, ipykernel package version should be >=6.11.0 When it is not the required version, we get "kernel usage not available" error or the some information of kernel usage is grayed out. I do not have the host cpu and host virtual memory data not shown here, because I have set the flag ResourceUseDisplay.show_host_usage=False

Proposed Solution

We could show a message mentioning that kernel needs at least ipykernel version > 6.11.0 to retrieve all the information, so that it would be clear to the users.

Additional context

[krassowski]

This appears to be a regression because a logic to check ipykernel version is already present, see #214. Also, ideally we would not be hard-coding ipykernel and allow other kernels to reply to these messages. I would prefer to add an ability to determine if kernel supports resource usage request instead (again, see #214).