Introduce minimal source coordinates (#623)

* split source.Location and create source.Coordinates for minimal path addressing

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

* move coordinates into separate file

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

* Update syft/source/coordinates.go

Co-authored-by: Dan Luhring <luhring@users.noreply.github.com>

internal/presenter/poweruser/test-fixtures/snapshot/TestJSONPresenter.golden

@@ -72,7 +72,7 @@
  ],
  "artifacts": [
   {
-   "id": "b84dfe0eb2c5670f",
+   "id": "962403cfb7be50d7",
    "name": "package-1",
    "version": "1.0.1",
    "type": "python",
@@ -102,7 +102,7 @@
    }
   },
   {
-   "id": "6619226d6979963f",
+   "id": "b11f44847bba0ed1",
    "name": "package-2",
    "version": "2.0.1",
    "type": "deb",