Import members from my.typo3.org API

As my.typo3.org provides an API with up-to-date membership information the importer should be switched to use that API. The documentation is here: https://docs.google.com/document/d/1CBpaKvV6pndds5SEL4vW7vFoJiVxMRQ-sQKEFABoMcM/edit

Response is looking like this:

[{"name":"Test Name","backlink":"https://typo3.org","membership":"COMMUNITY"}]

Membership possibilities:

• COMMUNITY
• [ACADEMIC_]BRONZE
• [ACADEMIC_]SILVER
• [ACADEMIC_]GOLD
• PLATINUM

The needed token to access that API is secured and should be included via Extension Configuration (to set it on production only).