adding support to filter on exception message

[oldzhu]

Expected behavior

-f can filter on exception name and exception messsage

Actual behavior

-f can only filter on exception name

Steps to reproduce the behavior

1. create a program which will throw an exception System.IOException("hahaha")
2. using the below command to filter on exception message.
   sudo procdump -e -f haha
3. Run the program and the dump wont be generated.

System information (e.g., distro, kernel version, etc.)