Add synchronization in server.Containers

This fixes races between ps and other operations
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
doc fix: remove trailing *

The trailing `*` makes it seem like there is some kind of annotation
Merge pull request #6842 from mrorii/patch-1

doc fix: remove trailing *
Remove dup tests

integration/server_test.go/TestCreateNumberUsername == integration-cli/docker_cli_run_test.go/TestUserByID
integration/server_test.go/TestRmi == integration-cli/docker_cli_images_test.go/TestCLIImageTagRemove

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
Merge pull request #6801 from cpuguy83/remove_dup_run_tests

Remove dup tests
Merge pull request #6771 from LK4D4/fix_containers_list_race

Add synchronization in server.Containers
Fix "Error while reading file" Fish completion

An unbalanced single quote caused Fish to fail to load the completion file with `source: Error while reading file “/etc/fish/completions/docker.fish”`.

Docker-DCO-1.1-Signed-off-by: Andrew France <andrew@avito.co.uk> (github: Odaeus)
Merge pull request #6852 from Odaeus/patch-1

Fix "Error while reading file" in Fish completion