Pglive

fixed leading line text format, ignoring tick format

- added CandleStick live plot support
- changed update_leading_text, x, y leading line text must be specified now. This was necessary change to display Candlestick plot data.
- typing update

Added plot_rate argument for DataConnector. This improves plot performance for high data rate. It allows plot to be repainted at specific rate. By default, plot is repainted after every new data point. Use this option if you don't want to skip any data points and display all data with reasonable performance.

- added support for PySide2 and PySide6
- fixed some PyQt5 examples, that were using PyQt6 instead

- fixed issue when leading line tick ignored LiveAxis string format
- LiveAxis, crosshair and leading line tick format is now unified

- fixed crosshair text formatting based on LiveAxis format
- added Qt Designer example