Make LCIO an optional dependency

[zaborowska]

BEGINRELEASENOTES

• Make LCIO an optional dependency. If LCIO is not found, some detectors (trackers) will not be built.

ENDRELEASENOTES

The list of the detectors in CMakeLists that depend on LCIO is hard-coded and needs to be modified for each new LCIO-dependent detector.

[andresailer]

Very nice. But is is better to be explicit about the use of LCIO or not to avoid confusion when it is present or not.

PS: I haven't tested the syntax of my proposed changes

[jmcarcell]

I have taken the liberty to apply the suggestions and fix the syntax, I'm sure Anna won't mind. With these changes I can build without LCIO, which means I can run native Key4hep algorithms without building any of the LCSoft packages.

[jmcarcell]

Some tests in CLICPerformance seem to be failing (from the downstream-build workflow), but they aren't related and I guess they are failing anyways:

lcio::IOException: [LCReader::open()] File(s) not found:  testCLIC_o3_v14.slcio  

so I'm going to merge this