v10.3-beta.1 release

This is a pre-release to test the decimal-based floating-point Saxon 10.3 in the wild.

The JAR might be called as Saxon via command-line.

For instance, in the root of the GitHub repository after executing a build via 'mvn clean install' the following might be executed by command line: (here file paths from Windows)
java -jar .\target\Saxon-HE-decimal-based-10.3-beta1.jar -s:src\test\resources\xml\in.xml -xsl:src\test\resources\xsl\test.xsl -o:target\generated-sources\out.xml

NOTE:
Currently round() is doing an EU commerce half-up rounding and not the to positive integer XPath rounding.
This should allow us to easily test our existing EU e-invoice validation artefacts, which is relying on XPath round() a lot.
The cleanest solution would be to provide user-functions of various rounding methods. Uncertain if Saxon is offering this in its Home Edition.