Fix: add sample_indices parameter to count_samples, plot_samples_interactive_map, plot_samples_bar, plot_sample_location_geo

[noir4201]

Closes #1126

## What this fixes
Four public methods that call sample_metadata() internally were missing
the sample_indices parameter that sample_metadata() exposes. This meant
users could not select samples by index when using these methods.

## Changes
Added sample_indices: Optional[base_params.sample_indices] = None to
the signatures of:

• count_samples()
• plot_samples_interactive_map()
• plot_samples_bar()
• plot_sample_location_geo()

And passed sample_indices=sample_indices through to the internal
sample_metadata() call in each method.

## Pattern followed
wgs_data_catalog() already correctly implements this pattern —
this PR applies the same approach to the four affected methods.

## Testing

1. All 1006 unit tests pass
2. ruff linting passes with no issues