Add support for location offsets #254
Description
Some linters report character offsets instead of line/column for issues.
We should support this:
- Setting to define if native format of linter, line/column, offset or both should be used.
- When offset is not available from linter, but settings enforces offset it is calculated for every issue
- When line/column is not available from linter, but settings enforces line/column it is calculated for every issue