FloorPlan gradle plugin

[julioz]

Adds Gradle Plugin implementation, with initial integration tests, sample project for manual end to end test and updates documentation.

floorPlan {
    schemaLocation = "$projectDir/schemas-dir".toString()
    outputLocation = "$projectDir/output-dir".toString()
    outputFormat {
        svg {
            enabled = true
        }
    }
}

Nice to haves (follow-ups):

• Output files stored within directories and preserve structure (Gradle Plugin: Preserve directory structure #33)
  • For example, <input_dir>/com.mypackage.mydatabase/1.json should end up as <output_dir>/com.mypackage.mydatabase/1.dbml
• Try out the Provider API (Use the Provider API for the Gradle Plugin properties #32)
  • Example
  • instead of String for the directory we can declare the field as DirectoryProperty and then to pass it, use something like project.layout.projectDirectory.dir("schemas"), so that the actual file will be resolved when the task runs
• Allow for closure.property = value in consumer's build.gradle, instead of forcing a full block like svg { enabled = true } (Gradle Plugin: Allow for one-line direct property definition #34)