String processing enhancement prerequisites for the upcoming `split_str_once` PR.
1. Add overloads of some string processing functions with a length parameter, to allow processing of substrings of C-strings
2. Add overloads of gr_printf that work with string lengths
3. Add constructors to `HUD_message_data` and `line_node`
4. Rename "size" to "len" in `vm_strndup` for clarity
5. Fill in some string attribute annotations
6. Make the rest of the HUD render functions `const`
7. Removed unneeded circular #includes in code/globalincs/memory/
Use a vector for storing the message queue so it can be whatever size the mission needs.
As part of this, add `free` and `vm_free` deleters to be usable with `unique_ptr` and enhance `insertion_sort` to be usable with vectors.
Fixes#4959.
This expands the existing system which only worked on Windows to all
supported platforms.
If the MSVC debug runtime is not present then its behavior is emulated
by adding a header to each allocated memory block.
Goober5000