Update MimeTypes, introduce precedence

[thekid]

This pull request updates the util.MimeTypes enumeration from https://cdn.jsdelivr.net/gh/jshttp/mime-db@latest/db.json, and adds a number of tests for well-known mime types.

Precedence used to resolve conflicts

• application/octet-stream: 0.1
• application/x-*: 0.7
• */vnd.*: 0.8
• application/*: 0.9

Script used to generate enumeration

https://gist.github.com/thekid/73ef0fbc0aea76031453cf6ec11528c5

[thekid]

A new API for mime types following their official name, "media types" (see https://www.iana.org/assignments/media-types/media-types.xhtml)

Definitions

• A media type is represented by its template
• A template consists of [type]/[subtype]
• A media type may have file extensions associated with it

Usage example

$types= MediaTypes::$DEFAULT;

// Lookups by file names or extensions => 'text/plain'
$template= $types->byFileName('test.txt')->template();
$template= $types->byExtension('.txt')->template();

// Shorthand
$template= $types->templateFor('test.txt');
$template= $types->templateFor('test.txt', default: 'application/octet-stream');

// Lookup by template
$type= $types->named('text/plain');
$type->template();   // 'text/plain'
$type->type();       // 'text'
$type->subtype();    // 'plain'
$type->extensions(); // ['.txt']

// Parse type and parameters
[$type, $parameters]= $types->parse('text/plain; charset=utf-8');
$type->template($parameters); // 'text/plain; charset=utf-8'