Change the way the gardenctl displays logs from loki

[Kristian-ZH]

What this PR does / why we need it:

1. Change the default value of tail flag from 200 to 1000, because if someone does not know about this flag, he will think that there is an issue with gardenctl logs/loki because very few logs are displayed

2. Change the way the gardenctl displays logs from loki.
   Now the logs will be visualised in the following way:

=============================================================================================
Pod Name kube-controller-manager-fsdfsd-fsdfs,  Container Name: kube-controller-manager, DockerID: dbcb643a5dfbbd12e8dbf50e497dab8
=============================================================================================
// logs
// logs
// logs
=============================================================================================
Pod Name kube-controller-manager-fsdfsd-fsdfs, Container Name: kube-controller-manager, DockerID: fsdfsdgsfsgsfsfsfs
=============================================================================================
//logs
//logs
//logs
=============================================================================================
Pod Name side-car-fsdfsd-fsdfs, Container Name: kube-controller-side-car-container, DockerID: 31241321413132
=============================================================================================
// logs
// logs
// logs

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Release note:

New format of the `gardenctl logs --loki` command

[tedteng]

It looks good.
just one comment, I am not clear the docker id in there. Is that represent history Pod? eg. api-server has been restarted, the DockerID to distinguish previous Pod and current live Pod? if Yes, is it possible to display the Pod name to identify it as well ?

============================================================================================
Container Name: kube-controller-manager, DockerID: dbcb643a5dfbbd12e8dbf50e497dab8
=============================================================================================
// logs
// logs
// logs
=============================================================================================
Container Name: kube-controller-manager, DockerID: fsdfsdgsfsgsfsfsfs
=============================================================================================```

[Kristian-ZH]

Is that represent history Pod? eg. api-server has been restarted, the DockerID to distinguish previous Pod and current live Pod?

Yes correct. In each container there is a running docker process. DockerID represents this process. If the DockerID is changed, it means that the the container has been restarted.

is it possible to display the Pod name to identify it as well ?

Yes, it is possible will do this today

[Kristian-ZH]

did the changes

[Kristian-ZH]

Аlso to emphasise that the current gardenctl logs --loki command does not work correctly. It sorts logs by stream, not by container as this PR does.
Each stream includes Severity label and this means that all logs with severity=Error will be displayed on one place, with severity=Info on another and so on.

[tedteng]

lgtm

[neo-liang-sap]

Per discussion with @Kristian-ZH i will merge this PR and trigger a minor release
BTW personally i didn't perform any test on this