bugfix: fix typeDefinition on backticked identifier

One of the short-circuiting conditions in the type definition logic was
a bit too broad, leading to `typeDefinition` not returning a result if
the position queried happened to precede a space in an identifier (see
the test that was added).

mtags/src/main/scala-2/scala/meta/internal/pc/PcDefinitionProvider.scala

@@ -2,7 +2,6 @@ package scala.meta.internal.pc
 
 import java.{util => ju}
 
-import scala.meta.internal.mtags.MtagsEnrichments._
 import scala.meta.internal.semanticdb.Scala._
 import scala.meta.pc.DefinitionResult
 import scala.meta.pc.OffsetParams
@@ -55,7 +54,7 @@ class PcDefinitionProvider(val compiler: MetalsGlobal, params: OffsetParams) {
   }
 
   private def definition(findTypeDef: Boolean): DefinitionResult = {
-    if (params.isWhitespace || params.isDelimiter || params.offset() == 0) {
+    if (params.offset() == 0) {
       DefinitionResultImpl.empty
     } else {
       val unit = addCompilationUnit(

tests/cross/src/test/scala/tests/typedef/TypeDefinitionSuite.scala

@@ -395,4 +395,13 @@ class TypeDefinitionSuite extends BasePcDefinitionSuite {
        |""".stripMargin
   )
 
+  check(
+    "backticked identifier",
+    """|
+       |class Main {
+       |  def `Foo/*scala/Int# Int.scala*/@@ Bar` = 1 + 2
+       |}
+       |""".stripMargin
+  )
+
 }