analysis/rta: Add ftrace based RTA analysis API
analysis/rta: Add ftrace based RTA analysis API

Since the merge of:

   https://github.com/scheduler-tools/rt-app/pull/80

rt-app has learn to inject useful events directly into a tracefile.

Those events are more suitable to write tests based on tracefile since the
rt-app generated events are in the same time domain of the kernel generated
events.

Add a new `rta` trace analysis API to access trace events generated by rt-app
and expose them as DataFrames. Add also a plotting API compliant to what the
PerfAnalysis based on logfile used to be.

Signed-off-by: Patrick Bellasi <431c86f368affbc3148c4669fbd465131f7e82cb@arm.com>

ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,credp/lisa,credp/lisa,credp/lisa,credp/lisa,ARM-software/lisa