Incorporate MicroProfile Config in RESTEasy

Currently, RESTEasy 3.x (targeted to Wildfly) uses servlet context-params to obtain configuration information. In RESTEasy 4.x, we have updated configuration to access all standard MicroProfile Config sources. Also, we have added three additional ConfigSources:

• servlet init-params (ordinal 60)
• filter init-params (ordinal 50)
• servlet context-params (ordinal 40)

In this feature request, we propose to port the relevant changes from RESTEasy 4.x to RESTEasy 3.x.

In RESTEasy 4.x, all parameters, both RESTEasy parameters and application parameters, are available from all ConfigSources to both RESTEasy and application code. In RESTEasy 3.x, we propose to add a RESTEasy parameter, "resteasy.config.resteasy.parameters.only", which, when set to "true", will limit the three RESTEasy ConfigSources to returning RESTEasy parameters only. It will default to "true".