As part of future changes to introduce support for EndOfLife.date
checking for Gradle, we noticed that we need to introduce the ability to
handle API responses of the form:

```json
  {
    "cycle": "8",
    "eol": false,
    "support": true,
  },
  {
    "cycle": "7",
    "eol": false,
    "support": false,
  },
  {
    "cycle": "6",
    "eol": "2023-02-10",
    "support": "2021-04-09",
  },
```

(Note that we have a different combination of boolean/ISO8601 dates for
the `eol` and `support` fields)

This was not something we needed to handle for the EndOfLife.date
Products that we implemented in the past, but is something we should
support.

To do this, we need to:

- add a new `is_eol` and `is_supported` column
- populate the `is_eol` and `is_supported` columns if the `eol` or
  `support` fields are not an ISO8601 date
- check the `is_eol` and `is_supported` columns when generating
  advisories