Fixes 2 Bugs and 13 Compiler Warnings (#10670)

* fixes: %g directive writing between 1 and 13 bytes into a region of size between 6 and 18 [-Wformat-overflow=]

* fixes: %5s directive writing between 5 and 63 bytes into a region of size 58 [-Wformat-overflow=]

* fixes: catching polymorphic type by value [-Wcatch-value=]

* fixes: [-Wcomment]; removes whitespaces

* increases buffer size from 71B to 90B to avoid potential ovfl.

src/libslic3r/GCode.cpp

@@ -5511,7 +5511,7 @@ LayerResult GCode::process_layer(
     // add tag for processor
     gcode += ";" + GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Layer_Change) + "\n";
     // export layer z
-    char buf[64];
+    char buf[80];
     sprintf(buf, print.is_BBL_printer() ? "; Z_HEIGHT: %g\n" : ";Z:%g\n", print_z);
     gcode += buf;
     // export layer height