These 2 large tables, `areaTexBytes` and `searchTexBytes`, contributed
~176kb worth of duplicate data into the `blender` executable due to the
header being used in multiple places. We were lucky that only 2
translation units had included this header so only 1 duplicate copy of
each was wasted.
Define the tables as `extern` to address this.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D12723
