[ruby/syntax_suggest] Fix typo for %I delimiter check

Also add tests for the other types which currently don't have one

ruby/syntax_suggest@db2dca2def

Author: Earlopain

lib/syntax_suggest/left_right_lex_count.rb

@@ -62,7 +62,7 @@ def count_lex(lex)
         # Means it's a string or a symbol `"{"` rather than being
         # part of a data structure (like a hash) `{ a: b }`
         # ignore it.
-      when :on_words_beg, :on_symbos_beg, :on_qwords_beg,
+      when :on_words_beg, :on_symbols_beg, :on_qwords_beg,
            :on_qsymbols_beg, :on_regexp_beg, :on_tstring_beg
         # ^^^
         # Handle shorthand syntaxes like `%Q{ i am a string }`