[FEATURE] Allow multiple sourceTargetMapping in the config file for the mcdev cdp command

[anasilva105]

Is your feature request related to a problem? Please describe.
I'm currently using the mcdev cdp command and I have a scenario where a I need to deploy both shared and non-shared data extensions using the same cdp branch. Shared Data Extensions can only be deployed using the ParentBU business unit. For this I need to have in my deploy folder a ParentBU folder with the shared DEs and the other business unit folders with non shared DEs.
Since we cannot have multiple sourceTargetMapping key-values configured this is not achievable.

Describe the solution you'd like
Multiple sourceTargetMapping key-values that would allow to create multiple source-target configurations.

Describe alternatives you've considered
In the current implementation I have tried to use multiple sourceTargetMapping configurations. The issue is that when mcdev cdp runs the deploy folder will get refreshed and not contain all the business units folders.

In the following example, the deploy folder will only contain the configuration given by the pair "deployment-source-shared": "deployment-target-shared", the first pair BUs was removed during the execution of mcdev cdp:

Additional context
Extension the ticket: #1918