icu: use separate .dat file for data
icu: use separate .dat file for data

This changes the build from using data embedded in libicudata.so
to using a separate .dat file which is then loaded.

This allows manipulation of this data using icu tools, and fixes
cross-compiling from little endian to big endian architectures,
as we can handle the endian conversion ourselves.

necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages