Standardize the name of the automation parameter used by select2 to submit the searched term

We have a couple of widgets based on select2. Each one gets suggestions from a backing automation operation by submitting the searched term under different automation param name depending on the operation:

• userSuggestion -> SuggestUserEntries.java -> "prefix"
• directorySuggestion -> SuggestDirectoryEntries.java -> "prefix"
• documentSuggestion -> DocumentPageProviderOperation.java -> "queryParams"
• custome operation -> "searchTerm"

This is a bit confusing and it'd be much nicer that it always submit the term under the same automation param name. But to do not break potential customer developments we need to maintain compatibility with current param names.

This could be possible with NXP-13597