When buffer gets resized, store the resized buffer in the pool

[lovromazgon]

Description

This PR contains a small but important change, where we make sure to return the resized buffer in the pool if needed. Previously we were always storing the default buffer (1kB) in the pool, even if it was resized to a bigger buffer in hostCall. This can be seen by observing the log messages warning about resizing the buffer for every call to the plugin:

2024-10-18T18:25:49+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183557 component=standalone.wasmProcessor processor_id=bench:foo
2024-10-18T18:25:49+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183559 component=standalone.wasmProcessor processor_id=bench:foo
2024-10-18T18:25:49+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183578 component=standalone.wasmProcessor processor_id=bench:foo
2024-10-18T18:25:50+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183623 component=standalone.wasmProcessor processor_id=bench:foo
2024-10-18T18:25:50+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183443 component=standalone.wasmProcessor processor_id=bench:foo
2024-10-18T18:25:50+00:00 WRN insufficient memory, command will be parked until next call to command_request allocated_bytes=1024 command_bytes=183492 component=standalone.wasmProcessor processor_id=bench:foo

After this change, the resizing happens only once, so only one log message is emitted.

Quick checks:

• There is no other pull request for the same update/change.
• I have written unit tests.
• I have made sure that the PR is of reasonable size and can be easily reviewed.