Value property to PyDom.Element and ElementCollection (#1828)

* add base test for input value field

* add value property to Element

* add test for non supported element

* prevent users to set value attribute on elements that do not support it

* add test for setting value on collections

* add value property to collection and add more tests

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

pyscript.core/src/stdlib/pyweb/pydom.py

@@ -131,6 +131,22 @@ class Element(BaseElement):
     def id(self, value):
         self._js.id = value
 
+    @property
+    def value(self):
+        return self._js.value
+
+    @value.setter
+    def value(self, value):
+        # in order to avoid confusion to the user, we don't allow setting the
+        # value of elements that don't have a value attribute
+        if not hasattr(self._js, "value"):
+            raise AttributeError(
+                f"Element {self._js.tagName} has no value attribute. If you want to "
+                "force a value attribute, set it directly using the `_js.value = <value>` "
+                "javascript API attribute instead."
+            )
+        self._js.value = value
+
     def clone(self, new_id=None):
         clone = Element(self._js.cloneNode(True))
         clone.id = new_id
@@ -264,6 +280,14 @@ class ElementCollection:
     def html(self, value):
         self._set_attribute("html", value)
 
+    @property
+    def value(self):
+        return self._get_attribute("value")
+
+    @value.setter
+    def value(self, value):
+        self._set_attribute("value", value)
+
     @property
     def children(self):
         return self._elements