Rationale of hardcoding resmgr_attr.msg_max_size in message_passing

### Description

In qnx_dispatch_engine, the msg_max_size is hardcoded to 2088 Bytes.

This leads to the problem that the max_send_size configuration of the client is not respected and the message_passing server discards messages bigger than 2088 bytes.

Can this can be made configurable?

### Error Occurrence Rate

Reproducible

### How to reproduce

The variable of concern is hard coded.
So the effect of discarded messages occurs every time this component is compiled and the binary is executed on QNX

### Supporting Information

The variable is hardcoded in the following line of the dispatch engine:
https://github.com/eclipse-score/communication/blob/29d6f943cfc47a70b2fed5e0cccfd886ea4f4e00/score/message_passing/qnx_dispatch/qnx_dispatch_engine.cpp#L141

### Classification

minor

### Affected Version

v0.3.0

### Category

- [ ] Safety Related
- [ ] Security Related

Start in score/message_passing/qnx_dispatch/qnx_dispatch_engine.cpp at line 141, where resmgr_attr.msg_max_size is hardcoded. Trace how the client’s max_send_size is configured and consumed by the QNX dispatch engine. Done means the configured client limit is respected and messages larger than 2088 bytes are no longer discarded solely because of the hardcoded value.

Written by the indexing model from the issue text.