Also adds auto upgrade from lower version based
on the .d.ts file (e.g. from version 3 to 4).
This is needed as we are now also capturing type aliases
in metadata files (and we rely on this),
see 6e3498ca8e.
- temporarily keeps the old sources under packages/tsc-wrapped
until the build scripts are changed to use compiler-cli everywhere.
- removes the compiler options `disableTransformerPipeline` that was introduced
in a previous beta of Angular 5, i.e. the transformer based compiler
is now always enabled.
PR Close#18966