Improve Matcher to allow matching attribute keys by regexp and unify API

[jacekbogdanski]

📝 Provide a description of the improvement

MatcherPattern should be extended with an option to match attribute key using RegExp. We should also unify patterns between attributes, styles, and classes, so the API is easier to use. Proposed changes using attributes example (they will:

// Match view element with any attribute value.
const pattern = {
	name: 'p',
	attributes: true
};

// Match view element which has matching attributes (String).
const pattern = {
	name: 'figure',
	attributes: 'title' // Match title attribute (can be empty).
};

// Match view element which has matching attributes (RegExp).
const pattern = {
	name: 'figure',
	attributes: /^data-.*$/ // Match attributes starting with `data-` e.g. `data-foo` with any value (can be empty).
};

// Match view element which has matching attributes (Object).
const pattern = {
	name: 'figure',
	attributes: {
		title: 'foobar',           // Match `title` attribute with 'foobar' value.
		alt: true,                 // Match `alt` attribute with any value (can be empty).
		'data-type': /^(jpg|png)$/ // Match `data-type` attribute with `jpg` or `png` value.
	}
};

// Match view element which has matching attributes (Array).
const pattern = {
	name: 'figure',
	attributes: [
		'title',    // Match `title` attribute (can be empty).
		/^data-*$/, // Match attributes starting with `data-` e.g. `data-foo` with any value (can be empty).
	]
};

// Match view element which has matching attributes (key-value-pairs).
const pattern = {
	name: 'input',
	attributes: [
		{
			key: 'type',                     // Match `type` as an attribute key.
			value: /^(text|number|date)$/ }, // Match `text`, `number` or `date` values.
		{
			key: /^data-.*$/,                // Match attributes starting with `data-` e.g. `data-foo`.
			value: true                      // Match any value (can be empty).
		}
	]
};

Some of the above patterns are already working but are not unified between attributes, styles, and classes. This improvement should also cover these cases.

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