File splitting naming puts trailing counter after file extension

[filoparra-ascari]

data_tamer/data_tamer_cpp/src/sinks/mcap_sink.cpp

Line 129 in e761f4f

filepath_ = original_filepath_ + "_" + std::to_string(file_reset_counter_);

If the sink is created by passing a full file path (including the file extension), this appends the trailing file_reset_counter_ after the .mcap extension. The file is still usable after a simple rename, so it's more of a nuisance than a major bug, but I thought it was still worth mentioning.