Make images.tags() returning a list of tags

[serhiy-storchaka]

After #899 images.tags() returns a list of images with tags instead of a list of tags (List[RemoteImage] instead of List[str]). It affected also the output of command neuro image tags which now outputs a list of full image URIs (unlike to neuro image ls which shorten URIs).

The documentation of command neuro image tags says only about a list of tags, not images. images.tags() is still not documented.

Returning a list of images from a method which does not contain "image" in name looks surprising to me. I think it would be better to make it returning a list of tags again. To help creating RemoteImage with tag we can add method RemoteImage.with_tag().

[serhiy-storchaka]

Two concurring PRs:

• Make "neuro image tags" outputting a list of tags instead of images #1743 changes just the output of neuro image tags and documents images.ls() and images.tags().
• Make images.ls() returning a list of tags instead of images #1744 changes also images.tags() and add RemoteImage.with_tag().