Compute embeddings with 2 or less images error

[PaulHax]

Steps

1. Drag Dataset Selection images slider to 2
2. Click Embeddings Compute button
3. Python Error: ValueError: n_components=3 must be between 0 and min(n_samples, n_features)=2 with svd_solver='full'

[vicentebolea]

This is a limitation of the pca|umap algorithm, the need a number of sample >= of the number of dimensions. We might want to limit the min number of elements in the sliders.