templates: Unify PV name prefixes, remove "Host"

The difference between host IOCs and embedded ones does not
justify having a different prefix.

src/template/base/top/exampleApp/Db/Makefile

@@ -14,7 +14,6 @@ DB += dbExample1.db
 DB += dbExample2.db
 DB += dbSubExample.db
 DB += user.substitutions
-DB += userHost.substitutions
 
 #----------------------------------------------------
 # If <anyname>.db template is not named <anyname>*.template add

src/template/base/top/exampleApp/Db/userHost.substitutions

@@ -1,12 +0,0 @@
-# Example substitutions file
-
-file "db/dbExample1.db" {
-    { user = "_USER_Host" }
-}
-
-file db/dbExample2.db {
-    pattern { user, no, scan }
-        { "_USER_Host", 1, "1 second" }
-        { "_USER_Host", 2, "2 second" }
-        { "_USER_Host", 3, "5 second" }
-}