Fixes errors such as
```
PHP Deprecated: strtolower(): Passing null to parameter #1 ($string) of type string is deprecated in /Users/Will/OpenSource/scummvm-web/include/Objects/File.php on line 26
```
I have proposed moving daily downloads of ScummVM and ScummVM Tools from `frs/daily/` to `frs/scummvm/daily/` and `frs/scummvm-tools/daily` respectively. This PR contains simplifications to the code that would result from this.
* WEB: Refactor reading files into FileUtils
Refactoring code in `include/Objects/File` into `FileUtils`. This not only makes the code much cleaner, but also allows it to be used in other places of the app, such as the `DownloadsModel`.
* WEB: Adding file size and extension to recommended downloads
In order to simplify the process of updating version downloads, [downloads spreadsheet table](https://docs.google.com/spreadsheets/d/1QzwFleEKXOsE59cYMOcQB7C2f0Np48uAQOCG8kicX_s/edit#gid=1057392663) now includes a `version` column and the `url` field is much simpler. In order to update a new version, simply change the value in the `version` field.
Further improvements can be made, but for now this is an improvement that keeps parity with the previous code.
It appears that at one point the data spreadsheet included a `type` field. This is no longer the case and so all of this is not used, providing unnecessary confusion and maintenance.
Now by default we're looking into local FS.
There are 3 potential places for files: frs/scummvm/, frs/scummvm-tools/
and downloads/. They're now governed by 'type' attribute to url.
Add a new XML field, "user_agent", used to find the user agent string
where the download item in question will be suggested to the user. Only
items with the "user_agent" field can be provided as recommended
downloads
Le Philousophe
Thunderforge
Mataniko
Eugene Sandulenko
Filippos Karapetis