Separate 'Feature ID' from 'Chemical/Compound' IDs and names

[Gscorreia89]

Refactor current featureMetadata fields to add improved "formal" fields for compound annotations.

The goal is to allow more text description of ion and compound ids at the same time. For example, the Feature Name/Unique ID could refer to a specific annotation: 'Histidine [M+H]+'. Then, Chemical/Compound ID and Name Fields could store unique identifiers about the annotated chemical compounds (Compound ID: CheBI/PubChem ID and 'Compound Name': Histidine.

This would require the following tasks:

1. Refactor the feature unique primary ID 'Feature Name' to 'Feature ID'
2. Keep 'Feature Name' as a text (or other) descriptor of a feature - ideally unique as well, but not required.
3. Add a new 'Compound Name' and 'Compound ID' to store chemical names and their identifiers.