unixodbc: Split libraries package into separate packages

unixodbc: Split libraries package into separate packages

This splits the unixodbc package into separate packages (libodbc,
libodbccr, libodbcinst). This also keeps the unixodbc package for
backwards compatibility.

The Internet News Server driver (libnn) is omitted as the driver README
describes it as "in mid-hack"[1] and it is doubtful if there is any
real-world use for it.

This also updates the package license information and URL, and sets
PKG_BUILD_PARALLEL and HOST_BUILD_PARALLEL.

[1]: https://github.com/lurcher/unixODBC/blob/9b31cd228d01e768a7ad9126d5da8860f1ed72a9/Drivers/nn/README#L17-L19

Signed-off-by: Jeffery To <jeffery.to@gmail.com>