No progress feedback for asdf plugin add commands

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

### Problem
`asdf plugin add java` and similar commands provide no visual feedback, making it unclear if the installation is working, stalled, or has failed.
### Steps to Reproduce

Run `asdf plugin add java`

- Terminal shows no progress indication
- User waits without knowing if the process is working

### Expected Behavior

- Show progress indicator (spinner/dots)
- Display status messages ("Downloading plugin...")

### Current Behavior

Silent operation that appears frozen

This particularly affects new users who may assume the tool is broken.

### Describe the proposed solution

- Add progress indicators during download/installation
- Show status messages at each step
- Ensure errors are clearly displayed

### Describe similar `asdf` features and why they are not sufficient

-

### Describe other workarounds you've considered

-

Start at the `asdf plugin add java` command entry point and reproduce the silent installation from a terminal. Trace the download and installation steps, then define completion as visible progress or status messages during work and clearly displayed errors on failure.

Written by the indexing model from the issue text.