[FIX] SDK: api.json transformer - link target applied to all links
[FIX] SDK: api.json transformer - link target applied to all links

The problem:
In the DemoKit API Reference links inside deprecated blocks open in new
tabs

The root cause:
For deprecated blocks sap.m.MessageStrip is used which internally uses
sap.m.FormattedText control. FormattedText control sets default link
target to "_blank" if no default link target is applied

The solution:
We add target for all local links

Note:
This is a sync change for the local API Reference preview with
Gerrit change: 3831671

Change-Id: Ied157d7c45980ce110687da5a6b3deac668aea29

SAP/openui5,SAP/openui5,SAP/openui5,SAP/openui5