Restructure output files

After the data model PR is merged, we need to improve the output structures,

• use the PURL strings to differentiate file names and store them in a cache directory
• create symlinks at artifact name-based files pointing to PURL-based file names to make them easier to find.
• move dependencies to a separate directory.

For example:

outputs/reports/github_com/FasterXML/jackson-databind/
├── result_data
│   ├── pkg_github_com_FasterXML_jackson-annotations_ef3b1dba42e1ef725fdaefd1aba92cba209bf012.html
│   ├── pkg_github_com_FasterXML_jackson-annotations_ef3b1dba42e1ef725fdaefd1aba92cba209bf012.json
│   ├── pkg_github_com_FasterXML_jackson-core_c94fd875fc430cb4b21154bb9d2320cf2693c305.html
│   ├── pkg_github_com_FasterXML_jackson-core_c94fd875fc430cb4b21154bb9d2320cf2693c305.json
│   ├── pkg_github_com_FasterXML_jackson-core_f3da625bb775a36c4b12abb4ed942d77f43214c2.html
│   ├── pkg_github_com_FasterXML_jackson-core_f3da625bb775a36c4b12abb4ed942d77f43214c2.json
│   ├── pkg_github_com_FasterXML_jackson-databind_a1e6208fd8c6d1873ae41106eb58f8c3751a12f3.html
│   ├── pkg_github_com_FasterXML_jackson-databind_a1e6208fd8c6d1873ae41106eb58f8c3751a12f3.json
│   ├── pkg_github_com_FasterXML_jackson-databind_a1e6208fd8c6d1873ae41106eb58f8c3751a12f3_dependencies.json
│   ├── pkg_github_com_junit-team_junit4_16228f3ccea3c6f1170488e0e268f3601d130f75.html
│   ├── pkg_github_com_junit-team_junit4_16228f3ccea3c6f1170488e0e268f3601d130f75.json
│   ├── pkg_github_com_powermock_powermock_a0be5c4bbeb04f13a6aec2653c1f5663cece1316.html
│   └── pkg_github_com_powermock_powermock_a0be5c4bbeb04f13a6aec2653c1f5663cece1316.json
├── dependencies
│   ├── dependencies.json
│   ├── jackson-annotations.html
│   ├── jackson-annotations.json
│   ├── jackson-core.html
│   ├── jackson-core.json
│   ├── junit4.html
│   ├── junit4.json
│   ├── powermock.html
│   └── powermock.json
├── jackson-databind.html
└── jackson-databind.json