Decompile most effect files in "code" (#144)

- `z_effect`: Matched and essentially all documented.
- `z_eff_spark.c`: Decompiled (1 non matching left) and mostly documented.
- `z_eff_shield_particle.c`: Matched and mostly documented.
- `z_eff_blure.c`: Decompiled (5 non matchings left) and partially documented.
- `z_effect_soft_sprite.c`: Matched and mostly documented.
- `z_eff_ss_dead.c`: Matched but not documented.
- `z_effect_soft_sprite_dlftbls.c`: "Matched" (only data, contains the effect ss overlay table).
- `z_effect_soft_sprite_old_init.c`: Not decompiled, but functions are categorized by effect ss overlay. And they should be decompiled at the same time as their corresponding effect ss in the future.

Other changes:
- Added a lot of types/enums to `z64effect.h`and moved+renamed some structs from `z64.h` to this header
- Added effect ss overlay segments to `segment_symbols.h` and effect ss init vars to `initvars.h`
- Added a macro called `VTX_T` to generate a `Vtx_t` in the same style as `VTX`
- Fixed `flg_set.c` .bss to be in the right file
- Removed `tools/overlayhelpers/batchdisasm` since it's no longer relevant
- Removed unused leftover asm from recent PRs

src/code/code_800FD970.c

@@ -22,8 +22,8 @@ void Math_Rand_Seed(u32 seed) {
 }
 
 /**
- * Returns a pseudo-random floating-point number between 0.0f and 1.0f, by generating 
- * the next integer and masking it to an IEEE-754 compliant floating-point number 
+ * Returns a pseudo-random floating-point number between 0.0f and 1.0f, by generating
+ * the next integer and masking it to an IEEE-754 compliant floating-point number
  * between 1.0f and 2.0f, returning the result subtract 1.0f.
  */
 f32 Math_Rand_ZeroOne() {