Use external libmvt component

[TheZ3ro]

libmvt is a big component of Bugbane that is used to parse mvt-like acquisitions.
testing it on Android is burdensome, sometimes you want to parse multiple time an acquisition and check what is going wrong. this need an Android build + emulation every time.
also its tests cannot be done with simple JUnit tests cause of the Android dependency.

for all of the above reasons, libmvt is now a standalone component that runs both on Android and on the JVM.

this PR removes the bundled libmvt component in Bugbane and instead pull the standalone libmvt from https://jitpack.io.
for now jitpack.io is ok, in the future we might want to build our own releases and sign them, and also sign tags
this PR also adds a libmvtLocal gradle property in case the developer wants to compile Bugbane with a local version of libmvt instead of a remote one