allow session() to request a subtree of info

[Sniffleupagus]

allow pwnagotchi to make partial requests from bettercap

Description

added optional parameter to bettercap.session() that limits the data request to a subtree of the total
data. "session" is default behavior of dumping everything.

Motivation and Context

• I have raised an issue to propose this change (required)
  The default behavior sends back a lot of information. It includes all of the caplets and everything. Allowing requests for just the wifi section would reduce the amount of data pwnagotchi and bettercap are passing around all the time. It makes the requests more efficient. Most of the time its only looking for wifi anyway.

How Has This Been Tested?

Tested for months on active pwnagotchi. Used in bcinfo.py (Sniffleupagus/pwnagotchi-utils) for just fetching wifi stats.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• [X ] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ X] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• [ X] I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s