Introduce new advanced searching of mapsets

[AiAe]

How it works:
If we provide "advanced_search", the "search" query will be fully ignored, same thing goes for other query params, as long as "advanced_search" overwrites them, otherwise they will still be applied.

Currently supported filters:

Syntax	Target field	Accepted values
b	BPM	number
d	difficulty rating	number
k	game mode	=1 through =10
l	map length	number
ln	long-note percentage	number
s	ranked status	=r ranked, =u unranked, =c clan ranked
pc	map play count	number
lu	last-updated timestamp	Unix milliseconds
t	tag	=sv takes any search term we support, multiple also supported

Most filters also support >= and <=.

Few examples that can be tested:

advanced_search=camellia k=4 k=7 s=r d<10
advanced_search=ln>=30 pc>1000 lu>=1757001600000
advanced_search=d=8.5
advanced_search=t=sv d<5 s=u