By default, the template was using `src/main/templates` as the source directory
for templates. This has the benefit of properly isolating the templates from
the application classpath: the framework is then responsible for injecting them
to the app runtime in whatever suitable form: either untouched as sources (in
development mode), or precompiled (for production).
With this change, it is also possible to use `src/main/resources/templates` as
a source directory. It _may_ feel more natural to users (although I would disagree),
but it has the drawback that the jars have to be configured to _exclude_ those
resources, because by default whatever is in `src/main/resources` MUST be included
in a jar (independently of the run mode).
It is also possible for the user to configure additional source directories should
they want to.
This commit introduces a _convention plugin_ for RIFE2 support.
It provides a number of advantages:
- the build logic is clearly separated from the build script,
which now only contains user-specific configuration, like the
framework version or how to configure test logging
- it fixes a number of issues like hardcoded dependencies
(`dependsOn` is in general a mistake)
- it removes the need to resolve the agent path eagerly
- it makes the agent configurable
- it clearly separates the user classpath from the RIFE
classpath (both for precompiling templates and for the agent)
- template compilation is cached
- it avoids the abuse of `src/main/resources` to put
templates and uses a dedicated directory instead, which
removes the need for exclusions
In addition, this should make it relatively straightforward
to convert the convention plugin into a proper RIFE2 plugin,
by extracting the code in `build-logic` into its own
repository then publishing to the Gradle plugin portal.
