[TASK] Use strict typed properties in ext:dashboard

Many properties are already typesafe due to their type declaration
in class constructors. This patch introduces constructor property
promotion where possible and additionally adds type declarations
for some properties and function arguments.

Resolves: #99443
Releases: main
Signed-off-by: Torben Hansen <derhansen@gmail.com>
Change-Id: I46f5f9163d233210d23219b923c07ecd3fb8ced8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77241


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>