Add funtion getchildren

[karan96108]

Add child node traversal methods to Element class

Problem

Currently users need to switch between requests-html and lxml.etree to work with child nodes,
creating unnecessary complexity.

Implementation

Added two methods to Element class:

• children property - Returns list of direct child elements
• getchildren() method - Provides lxml.etree compatibility

Breaking Changes

None. Adds new functionality while maintaining backwards compatibility.

Usage

# Using property
for child in element.children:
    print(child.tag)

# Using lxml-compatible method 
for child in element.getchildren():
    print(child.tag)

[waldemarKunkel]

Hi @karan96108, just found this PR by chance. Would suggest this change:

Suggested change

	@property
	def children(self) -> List['Element']:
	"""Returns a list of child elements."""
	return [Element(element=child, url=self.url, default_encoding=self.default_encoding)
	for child in self.element.getchildren()]
	def getchildren(self) -> List['Element']:
	"""Returns a list of child elements (lxml compatibility method)."""
	return self.children
	def attrs(self) -> _Attrs:
	@property
	def children(self) -> List['Element']:
	"""Returns a list of child elements."""
	return [Element(element=child, url=self.url, default_encoding=self.default_encoding)
	for child in self.element.getchildren()]
	def getchildren(self) -> List['Element']:
	"""Returns a list of child elements (lxml compatibility method)."""
	return self.children
	@property
	def attrs(self) -> _Attrs: