[ALICE3] Add digitization for the forward tracker (#15620)

* [ALICE3] Merge forward disks (FT3) into TRK module

* [ALICE3] Add digitization for forward disks

* Please consider the following formatting changes

* Fixup whitespace

* Fix indentation in CMakeLists.txt

* Add curly braces for single-line if statements.

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Co-authored-by: ALICE Action Bot <alibuild@cern.ch>
Co-authored-by: Nicolò Jacazio <njacazio@users.noreply.github.com>

Author: 3 people

Detectors/Upgrades/ALICE3/CMakeLists.txt

@@ -14,7 +14,6 @@ add_subdirectory(TRK)
 add_subdirectory(GlobalReconstruction)
 add_subdirectory(ECal)
 add_subdirectory(FD3)
-add_subdirectory(FT3)
 add_subdirectory(FCT)
 add_subdirectory(AOD)
 add_subdirectory(IOTOF)