[TECHNICAL] Detekt: static code analyzer

[jesmrec]

Adding a new static code analyzer for Kotlin: https://detekt.dev/

TASKS

• [X] Research (if needed)
• [X] Create branch feature/detekt
• [X] Initial set up of the tool
• [X] First try to integrate in CI (github actions)
• [X] Launch the analyzer to get an initial set of existing code smells
• [X] Analyze the code smells and decide what to do with them
• [ ] Check if more rules should be added or removed from the set of existing rules
• [ ] Fix all code smells:
  • [ ] MaxLineLength: max 150 characters per line
  • [ ] ComplexMethod: check when https://github.com/owncloud/android/issues/4478 is done
  • [ ] LongMethod: refactor all methods with more than 100 lines
  • [ ] SwallowedException
  • [ ] UnusedPrivateMember
  • [ ] NestedBlockDepth -> refactor with more than 5
  • [ ] ReturnCount -> max 2
  • [ ] ComplexCondition
  • [ ] ForbiddenComment
  • [ ] EmptyFunctionBlock -> fix for no overriden methods
  • [ ] VariableNaming
  • [ ] ImplicitDefaultLocale
  • [ ] NewLineAtEndOfFile
  • [ ] UtilityClassWithPublicConstructor
  • [ ] EmptySecondaryConstructor
  • [ ] TooGenericExceptionThrown
  • [ ] PrintStackTrace
  • [ ] MemberNameEqualsClassName
  • [ ] FunctionOnlyReturningConstant
  • [ ] MandatoryBracesLoops
  • [ ] WildCardImport
  • [ ] LoopWithTooManyJumpStatements
  • [ ] InstanceOfCheckForException
• [ ] Final CI setup (correct branching and setup ready to go)
• [ ] No code smells -> green CI
• [ ] Add Calens file
• [ ] Code review and apply changes requested
• [ ] Merge branch feature/detekt into master

[jesmrec]

Some dependency on https://github.com/owncloud/android/issues/4478.

Gradle version to push on, will determine the basic detekt version to use