[FEATURE] Add a parameter for text output instead of using callback_handler behavior

[zastrowm]

Problem Statement

We've received some feedback around:

I would like Strands to have an explicit parameter to enable/disable the default text output of what the agent is doing.

Proposed Solution

Add a new agent parameter (name TBD) which specifies if output is enabled or disabled:

agent = Agent(verbose=False) # turns off output
agent = Agent(verbose=True) # turns on output

Use Case

• I want to use a callback_handler and enable output
• I want a more explicit way of turning off output instead of Agent(callback_handler=None)

Alternatives Solutions

No response

Additional Context

No response