[CAMEL-7429] Camel Properties Component concatenation issue

Hi all,

This pull request is related to
**https://issues.apache.org/jira/browse/CAMEL-7429**

I added a new private method in the **DefaultPropertiesParser** class to determine if the property we're parsing is a concatenation with the aim to distinguish it from a nesting.

I added an **AllPropertiesTest** test class (SuiteTest) to execute all the tests related to Properties when some improvements or patches are added. I have improved the Tests with a new class **PropertiesComponentConcatenatePropertiesTest** where I test the new DefaultPropertiesParser.

Hope this should be useful.

Thanks.

Bye