Pull request #58: AG-2144 implement matches-property pseudo

Merge in EXTENSIONS/extended-css from feature/AG-2144 to master

* commit '7b2ba4660f2402fc064838a187191c6459373189':
  few tiny edits
  fix readme typo
  handle 'null' and 'undefined' property values set as string
  refactor utils, add matcherUtils tests, update readme
  refactor parseRawPropChain
  handle null as value while comparing, add extra tests for regexp chain props
  implement matches-property pseudo

README.md

@@ -8,6 +8,7 @@ Module for applying CSS styles with extended selection properties.
   * [Pseudo-class :contains()](#extended-css-contains)
   * [Pseudo-class :matches-css()](#extended-css-matches-css)
   * [Pseudo-class :matches-attr()](#extended-css-matches-attr)
+  * [Pseudo-class :matches-property()](#extended-css-matches-property)
   * [Pseudo-class :xpath()](#extended-css-xpath)
   * [Pseudo-class :nth-ancestor()](#extended-css-nth-ancestor)
   * [Pseudo-class :upward()](#extended-css-upward)
@@ -240,6 +241,63 @@ div:matches-attr("/-unit/"="/click/"):has(> span:contains(ads))
 *[class]:matches-attr("/.{5,}delay$/"="/^[0-9]*$/"):upward(2)
 ```
 
+<a id="extended-css-matches-property"></a>
+### Pseudo-class `:matches-property()`
+
+This pseudo-class allows to select an element by its properties.
+
+**Syntax**
+```
+selector:matches-property("name"[="value"])
+```
+
+- `name` — property name OR regular expression for property name
+- `value` — optional, property value OR regular expression for property value
+
+> For regex patterns, `"` and `\` should be escaped.
+
+> `name` supports regexp for property in chain, e.g. `prop./^unit[\\d]{4}$/.type`
+
+**Examples**
+
+```javascript
+divProperties = {
+    id: 1,
+    check: {
+        track: true,
+        unit_2ksdf1: true,
+    },
+    memoizedProps: {
+        key: null,
+        tag: 12,
+        _owner: {
+            effectTag: 1,
+            src: 'ad.com',
+        },
+    },
+};
+```
+
+```
+// element with such properties can be matched by any of such rules:
+
+div:matches-property("check.track")
+
+div:matches-property("check./^unit_.{4,6}$/"))
+
+div:matches-property("memoizedProps.key"="null")
+
+div:matches-property("memoizedProps._owner.src"="/ad/")
+```
+
+<details>
+  <summary><b>For filters maintainers</b></summary>
+
+  To check properties of specific element, do:
+  1. Select the element on the page.
+  2. Go to Console tab and run `console.dir($0)`.
+</details>
+
 <a id="extended-css-xpath"></a>
 ### Pseudo-class `:xpath()`