* CLI command to fetch control plane metrics
Fixes#3116
* Add GetResonse method to return http GET response
* Implemented timeouts using waitgroups
* Refactor metrics command by extracting common code to metrics_diagnostics_util
* Refactor diagnostics to remove code duplication
* Update portforward_test for NewContainerMetricsForward function
* Lint code
* Incorporate Alex's suggestions
* Lint code
* fix minor errors
* Add unit test for getAllContainersWithPort
* Update metrics and diagnostics to store results in a buffer and print once
* Incorporate Ivan's suggestions
* consistent error handling inside diagnostics
* add coloring for the output
* spawn goroutines for each pod instead of each container
* switch back to unbuffered channel
* remove coloring in the output
* Add a long description of the command
Signed-off-by: Saurav Tiwary <srv.twry@gmail.com>
Saurav Tiwary