➕ Add "getAllGarages" export and function

[Jordan2139]

Describe Pull request
This PR is fairly simple and simply aims to add in the export getAllGarages. I personally would like the ability to get all QB-Core garages and their data so I can use it in another resource.

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? [yes]
• Does your code fit the style guidelines? [yes]
• Does your PR fit the contribution guidelines? [yes]

[Sharkiiie]

I don't see this being something the majority of people would use.
What was the use case here?

[Jordan2139]

Its use case is in a QB-Core management panel, this is used to get all the garages to then be able to give people vehicles and choose what garage it goes to