Remove unfinished code.

Change-Id: Iee9e2ff03fc1bce45965148a772c0984a0a9f8d0
fdo#74132: Do not interrupt search in Writer.

Instead of "Do you want to continue at the beginning?" dialog,
just inform that we were at the end of the document in new label.

Also replace 'Search key not found' dialog with label.

Change-Id: I6a140cbad93406b73996f87a6d05fcc5d245fdbf