fix(leo): highlights fixes (#5563)

* make sure affine_group has priority, so parens and comma will not be miscolored; added `annotation` as @attribute

* `then` is not used as conditional, so moved to keywords

* finalize function highlight added

* differentiate between constant and variable variable identifiers

queries/leo/highlights.scm

@@ -1,4 +1,5 @@
-(variable) @variable
+(variable_identifier) @variable
+(constant_identifier) @constant
 
 [
  "assert"
@@ -13,6 +14,7 @@
  "record"
  "self"
  "struct"
+ "then"
 ] @keyword
 
  "in" @keyword.operator
@@ -43,7 +45,6 @@
 [ 
   "else"
   "if"
-  "then"
 ] @conditional
 
 [
@@ -143,6 +144,9 @@
 (transition_declaration
   name: (identifier) @function.builtin)
 
+(finalizer
+  name: (identifier) @function.builtin)
+
 (free_function_call
   (identifier) @function.call)
 
@@ -168,10 +172,12 @@
 
 [ 
   (address_literal)
-  (affine_group_literal) 
+  ((affine_group_literal) (#set! "priority" 101))
   (field_literal) 
   (product_group_literal) 
   (scalar_literal) 
   (signed_literal) 
   (unsigned_literal) 
 ] @number
+
+(annotation) @attribute