Stream package contents over gRPC

[mozesl-nokia]

Currently, the gRPC requests send packages wholesale, meaning that large packages have a large memory overhead on both sides.

Introduce chunking/streaming of package contents in all places where gRPC is used. The suggested chunk size is 1MiB, but this can be discussed.

[nagygergo]

@mozesl-nokia, is this NBI of porch server, or functions taking the podevaluator path?

[mozesl-nokia]

@nagygergo This should apply to anything using gRPC, so porch-server -> function-runner and podevaluator -> wrapper-server