Creation of the sky130_fd_bd_sram, SKY130 SRAM build space.

This commit contains major improvements to all files by regenerating
from original data, improving consistency and automated cross checking
of data.

Notable improvements include;

 * Integration of support cells required to use the OpenRAM memory
   compiler.

 * Creation of single port SRAM cells with built in OPC correction
   layers when laid out in an array.

 * Creation of dual port SRAM cells with built in OPC correction layers
   when laid out in an array.

 * Catalog and other library aggregations are now automatically
   generated from library contents (compared to previous hand created
   versions).

 * Significant improvements to documentation for all cells, including
   producing graphical representations, verified metadata and
   descriptions.

 * Names have been cross referenced between file types (such as
   simulation, layout, schematic and timing) and now verified to match.

 * Names have been improved to fix a standard format across all supported
   libraries and PDK contents.

 * Too many numerous other changes to list here.

Signed-off-by: Kevin Kelley <kevin.kelley@skywatertechnology.com>
Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>