feat!: Force user to delete regions by name; introduce +all specifier

[Restioson]

• Force the user to specify which regions they want to remove with /map region remove here <name>. This is a breaking change with regard to the command syntax, as <name> is a required parameter.
• Allow most local regions to be specified by +all which includes all that the player is inside of. This is a breaking change as now region markers beginning with + are invalid.

@haykam821: this is similar to what we discussed, but instead of using @all (@ is not allowed in word string args), it uses +all, and then makes +all a reserved region name. Unfortunately I had to reintroduce this as siblings would be very messy and don't compose well at all.

Partially addresses #21

[Restioson]

To clarify what I discussed with you previously on Discord, we can still introduce new functionality here without removing the ability to use a certain region name.

Don't worry - the current changeset does not add any reserved words