fedsd does not work with Pandas 2.0

[edwardalee]

The fedsd utility for generating sequence diagrams fails with Pandas 2.0 with the following error:

Building the communication diagram for the following trace files: federate__c.lft federate__i.lft federate__t.lft rti.lft in trace_svg.html
Traceback (most recent call last):
  File "/Users/eal/lingua-franca-intellij/util/tracing/visualization/fedsd.py", line 137, in <module>
    trace_df = trace_df.append(fed_df, sort=False, ignore_index=True)
               ^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/generic.py", line 5989, in __getattr__
    return object.__getattribute__(self, name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'DataFrame' object has no attribute 'append'. Did you mean: '_append'?

According to this page, append has been removed and must be replaced with concat.