Feature Request: Enable client installer to accept command line arguments for assigning labels at installation time

**Environment**
N/A

**Describe the issue**
Per-client label assignment in the GUI is tedious
Assigning labels to hosts at client install requires repacking the clients for every different desired label

Enabling command line arguments for the client installer like:

`GRR_3.4.6.0_amd64.exe --label=Incident_2023.43_Smith`

could enable more efficient scripted installs

**Error logs**
N/A

**Additional context**
N/A