When appending a source list, it should be filtered by platform name

[schettn]

Describe the feature or change you'd like
Currently when attaching a source list with mixed Github and Gitlab orders, the source objects are attached by order. Since the basic data of the profile should be taken from a github source object, these must also be appended first.

To achieve this following changes are required:

• Sort the source list by platform name in order ["github", "gitlab"]