[Feature] Advanced search

[bpatrik]

PiGallery should support search queries like:

• Landscape photos of John with Katie within 10km of New York between 02/04/2018 and 05/08/2019
• Two persons out of John, Katie, Bob and Alice
• etc..

[mcdamo]

Simple keyword searches with implied 'and' would be good:

• John, New York

Add other operators such as 'not':

• John, New York, !Katie

[bpatrik]

Implemented Advanced Search as Beta.
Did a lot of tests, and took me longer than expected to roll it out. Pls report if you see any issue with it.