Incorporate feedback

changelogs/unreleased/zj-format-chat-messages.yml

lib/gitlab/chat_commands/issue_create.rb

lib/gitlab/chat_commands/presenters/access.rb

lib/gitlab/chat_commands/presenters/base.rb

lib/gitlab/chat_commands/presenters/deploy.rb

lib/gitlab/chat_commands/presenters/help.rb

lib/gitlab/chat_commands/presenters/issuable.rb

lib/gitlab/chat_commands/presenters/list_issues.rb

lib/gitlab/chat_commands/presenters/new_issue.rb

lib/gitlab/chat_commands/presenters/show_issue.rb

spec/lib/gitlab/chat_commands/issue_search_spec.rb

spec/lib/gitlab/chat_commands/issue_show_spec.rb

spec/lib/gitlab/chat_commands/presenters/deploy_spec.rb

spec/lib/gitlab/chat_commands/presenters/list_issues_spec.rb

spec/lib/gitlab/chat_commands/presenters/show_issue_spec.rb

spec/lib/mattermost/client_spec.rb

spec/lib/mattermost/command_spec.rb

spec/lib/mattermost/session_spec.rb

spec/lib/mattermost/team_spec.rb