Previously, Rocto would issue an error when clients sent queries exceeding 32KiB in length. This was due to reliance on a statically allocated buffer shared between `read_message` and `read_bytes`. This issue is now fixed by using a dynamically allocated buffer for these functions and resizing as necessary.

To implement this, `read_message` was revised to accept pointers to both the relevant buffer and its size variable, both of which are updated if/when the buffer needs to be expanded. In turn, this required changes to both uses of `read_message`, one in `rocto_main_loop.c` and the other in `rocto.c`. A new `TPC017` test case was added to validate this behavior. Also, `test_read_message.c` was updated to account for the interface changes to `read_message`.

A number of `ydb_buffer_t*`s previously relied on fixed size buffers for their `buf_addr` members, but these cases needed to be revised to support dynamic buffer resizing. To f...