Mojarras Service Loader can't parse comments (#)

[Master-Code-Programmer]

Describe the bug

According to the official documentation of Javas Service Loader it may contain comments. Everything which comes after the '#' is considered a comment. Reference: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/ServiceLoader.html.
But Mojarras own Service Loader implementation doesn't support comments. It even doesn't skip blank lines. This leads to unexpected behaviour when using Mojarras Service Loader. When files under META-INF/services are loaded from Mojarras Service Loader it may lead to exceptions, while these service files under any other META-INF/services directory may perform perfect when they're loaded by the JDK Service Loader.

Therefore I implemented a Pull-Request which fixes that, so comments and blank lines don't lead to crashes when loading service files.

I also added unit tests to test the new functionality. To an area which had previously no test coverage at all.

I also replaced the magic string "UTF-8" with StandardCharsets.UTF_8 in the method I updated. It was introduced with Java 7 and can therefore also be used in a project where downwards compability is important.

Pull-Request: #5205

To Reproduce

Steps to reproduce the behavior:
Add a service file under META-INF/services, with a comment line, to a JAR which gets loaded and see how Mojarra fails to load a class named, for example # Copyright 2017, 2021 Eclipse Foundation. Eclipse License 2..

Expected behavior

Comments and blank lines are ignored.

P.S.: I read, understood and accepted the ECA.