In order to update catch2 the following changes were made:
- CMakeLists.txt: import catch2 with FetchContent_Declare, this will
  make it more flexible and easier to update
- removed main for tests, since it is not mandatory and it doesn't add
  any value of having it
- renaming includes in all the files

error: moving ‘a’ of type ‘arduino::String’ to itself [-Werror=self-move]
Which may happen if if GCC_VERSION is not defined, and instead __GNUC__
is defined

since for catch2 '[' is not a valid character in the tag name

The objective of error code class to wrap an integer that may be
returned from a function that may fail for different reasons. Since we
are not able to return values different from 0 in case of error in the
arduino language we need to wrap them into this class and redefine
boolean operator to mantain the same behaviour

The objective of ReturnValue is to maintain coherency with ErrorCode
class in cases where a single value is used to represent both the error
and the return value