Replace token with correct version in .nuspec

Replacement tokens aren't working as expected when .nuspec file is
in different directory and with different name as project files.
The version tag can still be overridden with -Version option on
nuget pack.

DEVSIX-1687

Author: IdamkinI

itext/itext.font-asian/iText Asian Font.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2011/08/nuspec.xsd">
   <metadata>
     <id>itext7.font-asian</id>
-    <version>$version$</version>
+    <version>7.1.0-SNAPSHOT</version>
     <title>iText 7 Asian Font</title>
     <authors>iText Software</authors>
     <owners>iText Software</owners>

itext/itext.hyph/iText Hyph.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2011/08/nuspec.xsd">
   <metadata>
     <id>itext7.hyph</id>
-    <version>$version$</version>
+    <version>7.1.0-SNAPSHOT</version>
     <title>iText 7 Hyph</title>
     <authors>iText Software</authors>
     <owners>iText Software</owners>

itext7.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2011/08/nuspec.xsd">
   <metadata>
     <id>itext7</id>
-    <version>$version$</version>
+    <version>7.1.0-SNAPSHOT</version>
     <title>iText 7 Community</title>
     <authors>iText Software</authors>
     <owners>iText Software</owners>