Improve advanced search filters to allow complex filtering

[tigreped]

Problem 1)

With current filter, user is limited to a single query at a time.

That means, a user can't combine two searches in one. For example, if a user wants to filter all records of species A that occur in municipality B AND species C that occur in municipality D, this won't be possible.

He would have to filter both queries separately, download and use another tool in order to visualize both records together.

Problem 2)

If there is non normalized values, user can't use OR statements. Filter is limited to AND. Example:

Suppose user wants to group all records from collector Danny Vellez, but there are occurrences with the values "D. V.", "D. Vellez", "V., Danny", etc. If the user wants to consider all these occurrences in its result, that will not be possible, because adding each of these will provide an AND statement for these values and obviously no records will be returned, because there will be no record that satisfy this condition of having in one field multiple values.