Flatten the sidebar for Frappe HR

[ruchamahabal]

Is your feature request related to a problem? Please describe.

In v16 since now we have an app switcher, individual workspaces can move out of the HR and Payroll heads

The content on the main HR & Payroll workspace is mostly redundant. Can be merged into other workspaces or we can have one "Home" / "Setup" workspace to house the master doctypes

Describe the solution you'd like

No response

Describe the alternatives you've considered

No response

Additional context

No response