Scala 3 explicit implicits

[amumurst]

Give all public implicit def/val explicit type annotations which is required for compilation in scala 3

[amumurst]

To find all of these I have compiled locally with scala 3. To do this I had to..

• Published slick master locally with scala 3 support and use that
• Removed scala-reflect in build.sbt for scala 3
• Used play-json milestone M7
• Commented out all macros (scala.reflect.runtime usage)
• Changed 3-4 files to adhere to new slick changes

Then I used Intellijs "insert type annotation" on every compile error until it compiled :)

So except migrating the macros and releases of upstream libraries, this is all thats needed for scala 3 support :)

[tminglei]

Merged. Thanks! 👍