replace getPrevalent* and getTop* functions

[thpralas]

After mia PR https://github.com/microbiome/mia/pull/526 that renamed the following functions :

• getRareFeatures --> getRare

• getRareTaxa --> getRare

• getTopFeatures --> getTop

• getTopTaxa --> getTop

• getPrevalentFeatures --> getPrevalent

• getPrevalentTaxa --> getPrevalent

• getUniqueFeatures --> getUnique

• getUniqueTaxa --> getUnique

This PR replaces the getTop and getPrevalent functions used in miaViz.

[antagomir]

Conflicts to resolve.. seems otherwise good to me.

[antagomir]

up