This change makes the files which are part of this changeset comply to
the project's coding style rules as defined in .clang-format.
This required addition of some forward declarations and additional
dependencies into header files as some of them depended on the order of
header inclusion which was changed due to alphabetical ordering of
includes.
Background: .clang-format states "SortIncludes:true" which will force
re-ording of include-statements which in turn might break the build if
header file inclusion is not order-independent.
Signed-off-by: Florian Grandel <jerico.dev@gmail.com>
6b09d0e791