Get repository command

[g4s8]

Add get repository command to list all repositories (in optional organization) where current user has access:

• artictl get repository - works in a "flat" mode
• articlt get repository orgname - for "org" mode

The output could include these fields: name, type, user access mode, e.g.

NAME          |    TYPE  | ACCESS
my-registry   |  docker  | RW
mvn           |   maven  | R
js            |      npm | RW

API documentation is here: https://github.com/artipie/maven-adapter/

Ticket: #2

[orlovm]

At the moment artipie doesn't provide necessary api endpoints.
Waiting for a solution to the issue artipie/artipie#972