Apply suggestions from code review

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

runtime/queries/slint/highlights.scm

@@ -96,7 +96,7 @@
   op: (_) @operator)
 
 (if_statement
-  "if" @keyword.conditional)
+  "if" @keyword.control.conditional)
 
 (if_statement
   ":" @punctuation.delimiter)
@@ -105,13 +105,13 @@
   [
     "if"
     "else"
-  ] @keyword.conditional)
+  ] @keyword.control.conditional)
 
 (ternary_expression
   [
     "?"
     ":"
-  ] @keyword.conditional)
+  ] @keyword.control.conditional)
 
 ; Keywords:
 [
@@ -162,7 +162,7 @@
   [
     "for"
     "in"
-  ] @keyword.repeat)
+  ] @keyword.control.repeat)
 
 (for_loop
   ":" @punctuation.delimiter)
@@ -180,16 +180,16 @@
   "@image-url" @attribute)
 
 (imperative_block
-  "return" @keyword.return)
+  "return" @keyword.control.return)
 
 (import_statement
   [
     "import"
     "from"
-  ] @keyword.import)
+  ] @keyword.control.import)
 
 (import_type
-  "as" @keyword.import)
+  "as" @keyword.control.import)
 
 (property
   [