[Demo App] Create a separate alpha release version

[B3nz01d]

As A designer testing the demo app
I want to be able to test the app
So that I can easily identify the alpha version and the beta version and be able to compare the current version and the proposed update with the new code.

The objective is to make sure that when you load the production app, the beta version and the alpha version you have a separate icon and separate app to check.

(Note: We are in the process of renaming the app. We should only deal with this card once we have the final naming, in order not to redo the job another time - I need to link to the correct task that I will create when I have the new name)

[pylapp]

We have now the icons for #140.
We won't wait further for an hypthetical name for the demo app validated by the brand.
We can still keep the current bundle identifier as as base, and add prod / beta / alpha suffixes ; thus we won't rely or depend to much to the brand name.