analysis: Keep thread selection and follow CPU when switching traces

analysis: Keep thread selection and follow CPU when switching traces

Keep thread selection and follow CPU when switching traces in CPU Usage
View. The data is saved in a map in the trace context, so if the view
is closed, it will remember the thread selection and the followed CPU
for each trace when reopening.

Change-Id: I8c56d852a133d0615f58cdb3e8e6b965a7c2f73d
Signed-off-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/75600
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>