Add extra commands

Adding new commands to the bot, mostly for the organization to keep a track on everything.
The list of newly added commands follows below, along with some explanations on each command.

List all teams

/ver-equipas
List all teams. Provides the team name and team id of each team participating (ie with members). If a team has no members, it will not show on this commands output.

List all teams registered

/ver-equipas-registo
List all registered teams. Provides the team name and team id and entry code of each team registered. All teams created will appear.

View team details

/detalhes-equipa <team_id>
Used to list all details of a team. The team-id must be provided. It shows the team information (name, balance and ID) among with the list of elements.

View user details

/detalhes <@user|user-id>
Used to list details of a participant. The @user or user-id must be provided. It will return the name (as a Slack @mention), ID and team ID (if any) of the user.