perf(providers): make sure all services are singleton

[emoralesb05]

when using modules, make sure we reuse the instance provided by the parent module rather than creation a new instance.

all covalent services are meant to be singleton and app wise instances.

What's included?

• Added provider factories to either return the parent instance or create one if there is none.

Test Steps

• ng serve
• See all components working fine.
• To verify this works, you would need to import a module that has a service like http or media in app.module and then import it again in a submodule. You can see they will share the instance using augury

General Tests for Every PR

• ng serve --aot still works.
• npm run lint passes.
• npm test passes and code coverage is not lower.
• npm run build still works.