add SQL.js support

[vazra]

sql.js is a port of SQLite to Webassembly, by compiling the SQLite C code with Emscripten, with contributed math and string extension functions included. It uses a virtual database file stored in memory, and thus doesn't persist the changes made to the database. However, it allows you to import any existing sqlite file, and to export the created database as a JavaScript typed array.

Sql.js predates WebAssembly, and thus started as an asm.js project. It still supports asm.js for backwards compatibility.

[vazra]

It won't work now as Knex is not supporting webpack (ref : knex/knex#1128 ) which is embedded with CRA. so the option will be to eject/rewire the CRA to add knex as an external. I don't think that's required for now, as SQL.js will be mostly used by those who are working on Electron/NodeJS application for testing purpose. so closing this.

Please re-open if someone want implement this.