Enable Direct Execution of DAGs via Go Code

[yottahmd]

Overview
Implement the capability to execute DAGs directly from Go code.

Example Usage:

err := dagu.Start("someDAG", dagu.Params("FOO=BAR"))

Implementation
Expose the Start function as follows:

package dagu

// Start starts DAG execution with specified options
function Start(dagName string, opts ...options)

Additional Context

• https://github.com/dagu-dev/dagu/discussions/582#discussioncomment-9646677

[halalala222]

@yohamta Hi! Can i work on this issue ?!

[halalala222]

@yohamta
Hi! I want to know

1. a dagu.go & option.go file in root package dagu ?
   
2. use client to run/retry dag
   

[yottahmd]

Hi @halalala222, Thank you very much for the interest! That sounds great. Additionally we might also need to create the interface for dag.DAG and model.Status, etc. Sorry, this issue might still be in a half-baked state. I think it needs a bit more consideration.

[halalala222]

Ok! Thanks you ! I will try to work on other issue!!