Find a generic way to allow partial search terms in search calls

[jframi]

In various search use case, it can be useful to search using part of a term.
A good example is when someone is searching for a germplasm name and want to capture all possible spelling that breeders may have used, or want to retrieve all germplasms that match a specific prefix.
Implementations can use wildcards or specific options like 'starts with', 'ends with', 'contains', etc.
Seems the issue has already been discussed, but would it be useful to propose at the BrAPI specification level a generic mechanism to implement such behaviour in search calls?

[BrapiCoordinatorSelby]

Linking to #154

[daveneti]

We are using an approach to filter and sort various entities on fields and/or attributes. It would be easier to put this in branch on git hub, since I can cut and parse the code directly from our version.