Add support for fuzzy search function within $filter, etc.

[ralfhandl]

The $search functionality allows fuzzy searching across all properties, and is useful for finding entities that have something to do with a particular search term.

However, some engines may support content search on a particular field, and customers may want to combine such content searches with other predicates, for example:

/users?$filter=address/state eq 'WA' or search(jobTitle,'smith')

Note:

1. They specifically want job titles related to a "smith" (woodsmith, ironsmith, etc.), not last names related to "smith"
2. They want to logically "OR" this condition with other conditions within the $filter clause.

They can't do either #1 or #2 with $search today.

Proposal

Introduce a new string function, "search", which does a content search on the first parameter for the search text provided by the second parameter. The second parameter can support the same syntax as the $search query option.

Alternative names: "fuzzyMatch", "fuzzySearch", "contentMatch", "contentSearch"

Imported from ODATA-1594