The plugin should support template rules

**Is your feature request related to a problem? Please describe.**
When using custom i-Code plugins, it is impossible to import the results in SonarQube.

**Describe the solution you'd like**
The plugin should support template rules to allow the user to add custom results coming from custom i-Code plugins or from other tool exporting results in i-Code format.

**Describe alternatives you've considered**
`none`

**Additional context**
`none`

The issue proposes template-rule support for custom i-Code plugins and other tools exporting i-Code format, but names no files, tests, or entry points. Start by mapping how this Java SonarQube plugin currently imports i-Code results and how rules are defined. Done means custom i-Code results can be imported through template rules, with the behavior verified by appropriate tests.

Written by the indexing model from the issue text.