[C++][Parquet] Statically link Arrow symbols when building libarrow via ExternalProject

[asfimport]

see discussion in apache/parquet-cpp#231

Reporter: Wes McKinney / @wesm
Assignee: Wes McKinney / @wesm

_{Note: This issue was originally created as PARQUET-854. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Users need to also install Apache Arrow in general when using parquet-cpp. You can produce a fully statically linked build, but in this case you need the Arrow headers to be able to build applications against libparquet