add support from common trace format

[monperrus]

add support from common trace format to reuse existing visualization tools:

• https://github.com/spiermar/d3-flame-graph/
• https://github.com/brendangregg/FlameGraph

See also trace formats from https://www.eclipse.org/tracecompass/

and trace translators such as https://github.com/spiermar/burn

    Common Trace Format (CTF), including but not limited to:
        Linux LTTng kernel traces
        Linux LTTng-UST userspace traces
        Linux Perf traces converted to CTF
        Bare metal traces
        Integration with the LTTng-Analyses scripts
    Hardware traces (e.g. IEEE Nexus 5001 CTF conversion). See also this link.
    GDB traces for debugging
    The Best Trace Format (BTF) for OSEK
    The libpcap (Packet CAPture) format, for network traces
    Custom text or XML parsers that can be added right from the graphical interface by the user
    Can be extended to support various log or trace files.
    Provided by the TraceCompass Incubator:
        Linux FTrace raw textual format
        Google's trace event json format
        Additional Linux Perf2ctf traces features
        Android traces
        UFtrace format