[oshdb-filter] filter tags by numerical values

(possible) syntax: `key < value`, `key > value`, …

example: `lanes >= 2`

to clarify:
* [ ] what selector should do if the tag is not present? intuitively, neither `lanes >= 2` nor `lanes < 2` should not match a building. but shouldn't the selectors be complementary i.e. `lanes >= 2 or lanes < 2` should match everything (like `lanes = 2 or lanes != 2` matches everything)?!

> This issue was originally posted at GIScience/ohsome-api#65 and https://gitlab.gistools.geog.uni-heidelberg.de/giscience/big-data/ohsome/libs/ohsome-filter/-/issues/12