added several symbols and footprints

[jharvey]

@CDFER I added 7 segment red LED display, I double checked the below items.
-- This was done in KC8.
-- 3D model installed correctly
-- Draft board uploaded to JLCPCB to validate the part placement is correct.

[CDFER]

Sorry I didn't see this sooner but the symbols for extended components should only be in JLCPCB-Extended.kicad_sym becasue the code currently only supports having basic/prefered parts in the other .kicad_sym files and because of the daily updates it also causes tons of merge conflics. Right now I don't really have the time to manually fix you pull request but I might have the time in a couple months but for now if you want me to merge your changes you'll need to move your symbols to JLCPCB-Extended.kicad_sym and revert your changes to Connectors_Buttons, Diode-Packages, Diodes, ICs, and Transformers (.kicad_sym)

But otherwise thanks for your hard work :)