Bug 487303 - [Search] Remove "Classic Search" view

Do not contribute "Classic Search" view - it's non-functional on it's
own, just delegates to the "Search" view and has been deprecated for
years.

Change-Id: Ic37dd29d89556e7363ea8e46d52cdfacc566182c
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.text/+/186120
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Alexander Kurtakov <akurtako@redhat.com>