Bugfix: Incomplete and invalid bootstrap.sh settings.

Bugfix: Incomplete and invalid bootstrap.sh settings.

The build settings in `bootstrap.sh` is incomplete or invalid for various reasons.

Some of the build settings are now consistently present in the Multi value Objects array loop.

The `build_sources_script-mode` is now being loaded.

Many of the build settings are now properly being populated using the correct variable or settings names.

The `bootstrap_id()` is now being called where the `bootstrap_id()` call has been missing entirely.

Remove build settings that do not actually exist in the standard (like `defines_object_program`).

The `has-flags_library-mode` is now being properly used.