Easy access of the hooking methods

[flocked]

I updated the access to the hooking methods by using

• ObjectHook: Hooks methods of an object.
• ClassInstanceHook: Hooks methods of all instances of a class.
• ClassHook: Hooks class methods.

Like this the hooking methods are always named the same for object, class and class instances hooking:

ObjectHook(textfield).hookBefore(selector, closure: closure)
ClassInstanceHook(NSTextField.self).hookBefore(selector, closure: closure)
ClassInstance(NSTextField.self).hookBefore(selector, closure: closure)

It also provides easier hooking of NSObject properties using keyPaths:

• Hook getting a property: func hook<Value>(_ keyPath: KeyPath<T, Value>, closure: @escaping (_ object: T, _ original: Value)->(Value)) throws -> Token. Example:

ObjectHook(textField).hook(\.stringValue, closure: { object, value in
	return value.lowercased()
})

• Hook setting a property:func hook<Value>(set keyPath: WritableKeyPath<T, Value>, closure: @escaping (_ object: T, _ value: Value, _ original: (Value)->())->()) throws -> Token. Example:

ObjectHook(textField).hook(set: \.stringValue, closure: { object, value, original in
	// original is a closure to the original property setter that can be called optionally to set the property.
	original(value.lowercased())
})

• Hook after getting a property: func hookAfter<Value>(_ keyPath: WritableKeyPath<T, Value>, closure: @escaping (_ object: T,_ value: Value)->()) throws -> Token. Example:

ObjectHook(textField).hookAfter(\.stringValue, closure: { object, value in
	
})

• Hook after setting a property: func hookAfter<Value>(set keyPath: WritableKeyPath<T, Value>, closure: @escaping (_ object: T,_ value: Value)->()) throws -> Token. Example:

ObjectHook(textField).hookAfter(set: \.stringValue, closure: { object, newValue in
	
})

• Hook before getting a property: func hookBefore<Value>(_ keyPath: WritableKeyPath<T, Value>, closure: @escaping (_ object: T,_ value: Value)->()) throws -> Token.
• Hook before setting a property: func hookBefore <Value>(set keyPath: WritableKeyPath<T, Value>, closure: @escaping (_ object: T,_ value: Value)->()) throws -> Token.

[623637646]

Hi @flocked .Thank you so much for the contribution again. This PR is a huge one for some small improvement of user experience. Currently I don't have time to review it. Now only bug fixing and important features are acceptable. Sorry about it. Let's keep this PR, will consider it in the future if needed.