Added constant-current diode / current-limiting diode symbols

I would like to contribute the symbol for a constant-current diode. I have added both a small and a normal size symbol.

For a datasheet example see https://www.semitec-global.com/uploads/2022/01/P22-23-CRD.pdf

Finished symbol:

Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items:

• Remove the instructional content of this template
• Provide a URL to a datasheet for the symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the automated check scripts - fix any errors as required
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