Fix compilation errors in some situations.

[h2zero]

Fixes #234

[iranl]

I believe this issue was introduced in a recent update of ESP-IDF 5.3.
There is an issue about this here espressif/esp-idf#14840, which is already fixed by espressif/esp-nimble@ca6c617.

So not sure if this change on the side of esp-nimble-cpp is needed (at least not long term).

[h2zero]

Thanks, it will be needed as this commonly breaks due to NimBLE defining min/max in headers and conflicting anywhere we #include <string>. I'm inclined to keep this change here.