Support for filtering HTTP resp by body content

**Is your feature request related to a problem? Please describe.**
Support for filtering HTTP req/resp by body via a regex, add a flag to http subcommand such as: --body 'reqId=123'

**Describe the solution you'd like**
you should refer to this source file: `agent/protocol/http.go`

**Describe alternatives you've considered**
None

**Additional context**
None
