Settings unavailable for LV2 effects in macros

### Bug description

This "may" apply to all real-time enabled effects. I've only tested with LV2 effects.

When an LV2 effect is included in a macro, the effect settings are unavailable. The "Parameters" are always:
`Use_Preset=""`

Consequently, the actual effect of a macro will change if the effect is used outside of the macro with different settings than were used when the macro was created.

### Steps to reproduce

1. Add any LV2 effect to a macro
2. Set the required settings

### Expected behavior

The settings to be stored in the macro.

### Actual behavior

The settings are not stored in the macro

### Audacity Version

current master / alpha / nightly build

### Operating system

Linux

### Additional context

Same problem with current release (3.2.1) and 3.2.2 beta.

Reproduce the issue on Linux by adding an LV2 effect to a macro and changing its settings. Trace how macro Parameters store effect settings, then verify that the selected settings remain available when the effect is used outside the macro.

Written by the indexing model from the issue text.