Add resize to GPRT internal buffer object

[natevm]

This pattern of checking of a buffer size happens in a few places here. Could it be pushed down into the Buffer class somehow?

  This pattern of checking of a buffer size happens in a few places here. Could it be pushed down into the `Buffer` class somehow?

_Originally posted by @pshriwise in https://github.com/gprt-org/GPRT/pull/28#discussion_r1026366415_