Kermalis mega clean numero2

[Kermalis]

Continuing the work from my previous PR, I did these things:

• Split files that weren't supposed to be together. For example, Wigglytuff shop was originally multiple files, but was all in one massive .c file. I split those and added their data. A lot of data has been moved into src finally
• Create .h files for structs and code. This is unfinished but is necessary. For example, two .h files that reference structs within each other. The structs need to be moved to a separate structs file. This also makes compiling faster in general. Unnecessary extern functions aren't included if you only include the necessary structs. I hope to continue this for others (like wonder_mail.h)
• Clean up more NULL vs 0 vs FALSE
• Define more EWRAM_DATA/EWRAM_DATA_2/IWRAM_DATA and mark up file boundaries

This PR also tackled the massive block of strings that I call common_strings. It has some stuff used in most menus like "Info" or "Yes". For some reason, it also includes the dialogue for all the shops and the hints. It's pretty weird but that's what they did so I moved all of that out of data and now we have a simple #include "common_strings.h" instead of defining extern const *gCommonInfo[]; etc in dozens of files.

Also did some charmap work where it was needed

There's probably more I'm forgetting. I decomp'd some functions also, but only like 5 if I had to guess.

So here's stuff that needs to be finished in my next PR:

• Separate global structs from their .c/.h counterparts (like wonder_mail)
• Continue splitting/renaming/data for the massive files. Looking at the wonder_mail mess of .c files and also a few that I made comments in
• Continue removing externs
• Continue defining rigid file boundaries and making things static
• Continue cleaning up indentation etc (not that important but it helps me know a file is "done" for real)

[SethBarberee]

Is there a reason why we use structs versus sticking it in global.h like pokeemerald/pokefirered? Speed? Trying to understand the reasoning.