fix: move all typescript helpers to a separate file - ts-utils

[sis0k0]

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What is the current behavior?

The utils.ts module requires typescript. This causes all schematics requiring the utils.ts to also try to load typescript even if it's not needed. The typescript module is available when executing schematics in an Angular project because all Angular projects depend on typecsript. However, trying to load typescript when executing ng new will fail unless typescript is globally installed.

What is the new behavior?

The TypeScript helper functions are moved to a separate ts-utils.ts file.

Fixes #216.