Merge branch '#1068644-add-indexsearch-alias' into 'master'

#1068644: Add IndexSearchAlias for seamless Upgrade

See merge request xrm/basic!508

aliasDefinition/IndexSearchAlias/IndexSearchAlias.aod

+<?xml version="1.0" encoding="UTF-8"?>
+<aliasDefinition xmlns="http://www.adito.de/2018/ao/Model" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" VERSION="1.2.0" xsi:schemaLocation="http://www.adito.de/2018/ao/Model adito://models/xsd/aliasDefinition/1.2.0">
+  <name>IndexSearchAlias</name>
+  <majorModelMode>DISTRIBUTED</majorModelMode>
+  <datasourceType v="18" />
+</aliasDefinition>