Add `anchor` Attribute to `rio.Slider` Component

[Sn3llius]

It would be beneficial to enhance the rio.Slider component by introducing an additional attribute called anchor?. This attribute will accept a Literal type with values "left" or "right", defaulting to "left". This feature will make the rio.Slider more versatile and allow developers to specify the anchor position of the slider.

Benefits:

• Increased versatility of the rio.Slider component.
• Better alignment control in various UI layouts.
• Improved developer experience by providing more customization options.

Proposed API:

class Slider(FundamentalComponent):
    def __init__(self, ..., anchor: Literal["left", "right"] = "left"):

rio.Slider(..., anchor = "left") or rio.Slider(...):

rio.Slider(anchor = "right"):

Additional Context:

• Ensure the default behavior remains unchanged to maintain backward compatibility.
• Update relevant documentation to reflect the new attribute and its usage.