[docker-ptf] Add Tornado WSGI (sonic-net#21655)

Why I did it
This PR adds tornado Tornado WSGI package to docker-ptf image. This will enable replacing the Flask based ExaBGP process API with tornado-based application. Tornado handles large number of requests with higher payload sizes automatically while Flask+Werkzeug requires additional setting changes which can be avoided keeping the code cleaner.

Work item tracking
Microsoft ADO (number only): 31250273
How I did it
Added tornado package to the docker-ptf image.

How to verify it
Ran add, remove topology to check announce routes
Ran route stress test to verify it is stable

Which release branch to backport (provide reason below if selected)
 201811
 201911
 202006
 202012
 202106
 202111
 202205
 202211
 202305
Tested branch (Please provide the tested image version)
NA

Description for the changelog
[docker-ptf] Add Tornado WSGI

This PR adds tornado Tornado WSGI package to docker-ptf image. This will enable replacing the Flask based ExaBGP process API with tornado-based application. Tornado handles large number of requests with higher payload sizes automatically while Flask+Werkzeug requires additional setting changes which can be avoided keeping the code cleaner.

Author: opcoder0

dockers/docker-ptf/Dockerfile.j2

@@ -161,6 +161,7 @@ RUN rm -rf /debs \
     && pip install pysubnettree \
     && pip install paramiko \
     && pip install flask   \
+    && pip install tornado \
     && pip install exabgp==3.4.17\
     && pip install pyaml   \
     && pip install pybrctl pyro4 rpyc yabgp \
@@ -208,6 +209,7 @@ RUN pip3 install setuptools \
     && pip3 install ipaddress \
     && pip3 install pysubnettree \
     && pip3 install paramiko \
+    && pip3 install tornado \
     && pip3 install Flask   \
     && pip3 install exabgp \
     && pip3 install pyaml   \