deftype and defmethod syntax major changes (#3094)

Major change to how `deftype` shows up in our code:
- the decompiler will no longer emit the `offset-assert`,
`method-count-assert`, `size-assert` and `flag-assert` parameters. There
are extremely few cases where having this in the decompiled code is
helpful, as the types there come from `all-types` which already has
those parameters. This also doesn't break type consistency because:
  - the asserts aren't compared.
- the first step of the test uses `all-types`, which has the asserts,
which will throw an error if they're bad.
- the decompiler won't emit the `heap-base` parameter unless necessary
now.
- the decompiler will try its hardest to turn a fixed-offset field into
an `overlay-at` field. It falls back to the old offset if all else
fails.
- `overlay-at` now supports field "dereferencing" to specify the offset
that's within a field that's a structure, e.g.:
```lisp
(deftype foobar (structure)
  ((vec    vector  :inline)
   (flags  int32   :overlay-at (-> vec w))
   )
  )
```
in this structure, the offset of `flags` will be 12 because that is the
final offset of `vec`'s `w` field within this structure.
- **removed ID from all method declarations.** IDs are only ever
automatically assigned now. Fixes #3068.
- added an `:overlay` parameter to method declarations, in order to
declare a new method that goes on top of a previously-defined method.
Syntax is `:overlay <method-name>`. Please do not ever use this.
- added `state-methods` list parameter. This lets you quickly specify a
list of states to be put in the method table. Same syntax as the
`states` list parameter. The decompiler will try to put as many states
in this as it can without messing with the method ID order.

Also changes `defmethod` to make the first type definition (before the
arguments) optional. The type can now be inferred from the first
argument. Fixes #3093.

---------

Co-authored-by: Hat Kid <6624576+Hat-Kid@users.noreply.github.com>

test/decompiler/reference/jak2/engine/debug/viewer_REF.gc

@@ -10,19 +10,15 @@
 
 ;; definition of type viewer
 (deftype viewer (process-drawable)
-  ((janim art-joint-anim  :offset-assert 200)
+  ((janim  art-joint-anim)
    )
-  :heap-base #x50
-  :method-count-assert 20
-  :size-assert         #xcc
-  :flag-assert         #x14005000cc
   (:states
     viewer-process
     )
   )
 
 ;; definition for method 3 of type viewer
-(defmethod inspect viewer ((this viewer))
+(defmethod inspect ((this viewer))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -220,7 +216,7 @@
 
 ;; definition for method 11 of type viewer
 ;; WARN: Return type mismatch object vs none.
-(defmethod init-from-entity! viewer ((this viewer) (arg0 entity-actor))
+(defmethod init-from-entity! ((this viewer) (arg0 entity-actor))
   "Typically the method that does the initial setup on the process, potentially using the [[entity-actor]] provided as part of that.
 This commonly includes things such as:
 - stack size