Adjust owner in Interactive.contextOfPath causing crash in ImplicitSearch (#19875)

`Interactive` provided us with the method `contextOfPath` which should
return enclosing ctx for given position. It was working fine until given
loop detection was improved some time ago.

It started crashing as the context owner was set to original context
owner, instead of the real owner. This PR changes this and sets context
to its outer context owner.

Fixes scalameta/metals#6193

Author: rochala

Diff for: compiler/src/dotty/tools/dotc/interactive/Interactive.scala

@@ -297,14 +297,14 @@ object Interactive {
           else
             outer
         case tree @ Block(stats, expr) =>
-          val localCtx = outer.fresh.setNewScope
+          val localCtx = outer.localContext(tree, outer.owner).setNewScope
           stats.foreach {
             case stat: MemberDef => localCtx.enter(stat.symbol)
             case _ =>
           }
-          contextOfStat(stats, nested, ctx.owner, localCtx)
+          contextOfStat(stats, nested, localCtx.owner, localCtx)
         case tree @ CaseDef(pat, _, _) =>
-          val localCtx = outer.fresh.setNewScope
+          val localCtx = outer.localContext(tree, outer.owner).setNewScope
           pat.foreachSubTree {
             case bind: Bind => localCtx.enter(bind.symbol)
             case _ =>

Diff for: language-server/test/dotty/tools/languageserver/CompletionTest.scala

@@ -35,6 +35,20 @@ class CompletionTest {
       .completion(("Conversion", Class, "Conversion"))
   }
 
+  @Test def implicitSearchCrash: Unit =
+    code"""
+          |object Test:
+          |  trait Foo:
+          |    def test(): String
+          |  given Int = ???
+          |  given (using ev: Int): Conversion[String, Foo] = ???
+          |
+          |  val test = {
+          |    "".tes$m1
+          |    1
+          |  }"""
+      .completion(("test", Method, "(): String"))
+
   @Test def completionFromScalaPackageObject: Unit = {
     code"class Foo { val foo: BigD${m1} }"
       .completion(