Setup an initial database for local development

**Is your feature request related to a problem?**

This feature is to ease a developer's life when running the app for simple testing, or to test a specific feature.

I want to have a way to setup an initial database, when I run the project. If I run the project I don't want to have always to setup the entire dataset, I want the option to use an existing database.

Example: I want to clone run the project with the option to use dataset 1 with 3 users, 2 of them in a mentorship relation with a couple of tasks. Once this is loaded, when I run the project, I can test the local app knowing I have these already created.

**Describe the solution you'd like**

Not sure about the solution to be honest. Open for suggestions!

**Describe alternatives you've considered**

Broadly speaking... have a local environment variable to say if a data is to be loaded, and have a part of the code, such as feature toggle, that if that is set a specific dataset is loaded.

Be aware that, for user emails, this can be configured at anytime. Imagining i'm using temporary emails, not everyday I will have the same emails to work with, so emails should not be "set in stone".

**Additional context**

Maybe this can be solved in a way with #78 ... I'm not sure, but its worth mentioning.

_If anyone needs more clarification I'd be more than happy to help with this_