[TASK] Adapt install tool mail functions to use Swiftmailer

The mail sending functions in install tool use PHPs mail() function.
They should use instead the Swiftmailer.

Releases: 6.2
Resolves: #49366
Change-Id: I0d44150a37284804344793bfc34a89847b3ddb4b
Reviewed-on: https://review.typo3.org/21622
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters