Add QFN-28-1EP_4x4mm_P0.45mm_EP2.6x2.6mm

This QFN is intended to be used with the Everest Semi ES8388 audio codec.

Most of the dimensions are taken from datasheet revision 12.0, link http://www.everest-semi.com/pdf/ES8388%20DS.pdf . However, the package outline dimensions are taken from datasheet revision 5.0, link https://www.lcsc.com/datasheet/lcsc_datasheet_1912111437_Everest-semi-Everest-Semiconductor-ES8388_C365736.pdf .

In revision 12.0, the lead length dimension has looser tolerances than in revision 5.0. To be conservative, the looser tolerance is used.

In revision 12.0, the body size is not given with any tolerances, so the values from revision 5.0 have been used.

Screenshot of datasheet revision 12.0:

Screenshot of datasheet revision 5.0: