gitlab folder added

Description

.gitlab folder added and pull request template added

Related to solutions/tickets#100

Reviewers list

• @guillaume.everartsdevelp

Self Check:

Strike through any lines that are not applicable (~~line~~) then check the box

• Correct, in line with design
• Sufficient test cases (reproduces the bug/tests the requested feature)
• Code is clear and sufficiently documented (classes, methods and function docs, document important assumptions, link to reference materials)
• Type annotations
• Issue is in the review column
• MR is assigned to first reviewer