Fix wrong session ID 18446744073709551615 (overflow)

Problem

Frequently, for example when a drive clean-up process fails, the session ID 18446744073709551615 is used (-1 converted to uint64_t). This value ends up appearing across several drives, when this should not happen.

Example:

pcvlado ~ > cta-admin dr ls | egrep "session|18446744073709551615"
library    drive     host desired          request   status   since    vid        tapepool            vo  files   data  MB/s              session priority activity age reason
!IBM460 I4600213 tpsrv455    Down                -  CleanUp      37      -               -             -      -      -     - 18446744073709551615        0        -  37 [cta-taped] ERROR Cleaner failed. Failed ST i[...]
!IBM460 I4600231 tpsrv473    Down                -  CleanUp     232      -               -             -      -      -     - 18446744073709551615        0        - 232 [cta-taped] ERROR Cleaner failed. Failed ST i[...]
!IBM460 I4600841 tpsrv070    Down                -  CleanUp      33      -               -             -      -      -     - 18446744073709551615        0        -  33 [cta-taped] ERROR Cleaner failed. Failed ST i[...]
!IBM460 I4601432 tpsrv006    Down                -  CleanUp     150      -               -             -      -      -     - 18446744073709551615        0        - 150 [cta-taped] ERROR Cleaner failed. Failed ST i[...]
!IBM460 I4601433 tpsrv005    Down                -  CleanUp     169      -               -             -      -      -     - 18446744073709551615        0        - 169 [cta-taped] ERROR Cleaner failed. Failed ST i[...]

Objective

Find why this overflown value is used, and fix it (use a normal/unique ID instead).

References

Ops issue: https://gitlab.cern.ch/cta/operations/-/issues/1270