[suggestion] log message for FileNotFound exception not clear enough

[nonnenmacher]

when loading xml-routes from a file: reference, the log message when raising FileNotFoundException in org.apache.camel.quarkus.core.CamelRoutesCollector#collectXmlRoutesFromDirectory
is not explicit enough.

It log

catch (FileNotFoundException e) {
                LOGGER.debug("No XML routes found in {}. Skipping XML routes detection.", part);

instead of more explicitely output that it didn't find the file (hence no routes were added)

so one will see something like

2020-06-17 15:28:28,588 INFO  [org.apa.cam.qua.cor.CamelRoutesCollector] (Quarkus Main Thread) Loading additional Camel XML routes from: file:src/main/resources/routes/camel-routes.xml
2020-06-17 15:28:28,589 INFO  [org.apa.cam.imp.eng.AbstractCamelContext] (Quarkus Main Thread) Apache Camel 3.3.0 (CamelContext: camel-xml-route) is starting
2020-06-17 15:28:28,591 INFO  [org.apa.cam.imp.eng.AbstractCamelContext] (Quarkus Main Thread) StreamCaching is not in use. If using streams then its recommended to enable stream caching. See more details at http://camel.apache.org/stream-caching.html
2020-06-17 15:28:28,591 INFO  [org.apa.cam.imp.eng.AbstractCamelContext] (Quarkus Main Thread) *Total 0 routes, of which 0 are started*

And search for other reasons on the XML file itself instead of more simpler cause : didn't find the file: or class path: resource specified

NOTE : it would also be a nice to have an addendum about *absolute* path, in the `Example:file-split-log`, as when running it without attention on the indicated `application.properties`

is like

camel.context.name = camel-quarkus-xml
camel.main.xml-routes = file:src/main/resources/routes/camel-routes.xml
camel.file.route.folder = src/main/resources/file

Which lead to this specific misleading message.

[JiriOndrusek]

Please, assign to me.