fix(loader): module.decorator order of operations is now irrelevant

`module.decorator` is now processed via the configBlocks order of operations and:
  1. no longer throws error if declared before the provider being decorated.
  2. guarantees the correct provider will be decorated when multiple, same-name
  providers are defined.

(1) Prior to this fix, declaring `module.decorator` before the provider that it
decorates results in throwing an error:

```js
angular
  .module('theApp', [])
  .decorator('theFactory', moduleDecoratorFn)
  .factory('theFactory', theFactoryFn);

// Error: [$injector:modulerr] Failed to instantiate module theApp due to:
// Error: [$injector:unpr] Unknown provider: theFactoryProvider
```

The result of this fix now allows for the declaration order above.

(2) Prior to this fix, declaring `module.decorator` before the final, same-named
provider results in that provider **not** being decorated as expected:

**NOTE:** Angular does not use provider name spacing, so the final declared
provider is selected if multiple, same-named providers are declared.

```js
angular
  .module('theApp', [])
  .factory('theFactory', theFactoryFn)
  .decorator('theFactory', moduleDecoratorFn)
  .factory('theFactory', theOtherFactoryFn);
```

`theOtherFactoryFn` is selected as 'theFactory' provider, but prior to this fix it is **not**
decorated via `moduleDecoratorFn`. This fix ensures that `theOtherFactoryFn` will be decorated as
expected when using the declaration order above.

Closes #12382
Closes #14348

BREAKING CHANGE:

`module.decorator` declarations are now processed as part of the `module.config`
queue and may result in providers being decorated in a different order if
`module.config` blocks are also used to decorate providers via
`$provide.decorator`.

For example, consider the following declaration order in which 'theFactory' is
decorated by both a `module.decorator` and a `$provide.decorator`:

```js
angular
  .module('theApp', [])
  .factory('theFactory', theFactoryFn)
  .config(function($provide) {
    $provide.decorator('theFactory', provideDecoratorFn);
  })
  .decorator('theFactory', moduleDecoratorFn);
```

Prior to this fix, 'theFactory' provider would be decorated in the following
order:
  1. moduleDecoratorFn
  2. provideDecoratorFn

The result of this fix changes the order in which 'theFactory' is decorated
because now `module.decorator` declarations are processed in the same order as
`module.config` declarations:
  1. provideDecoratorFn
  2. moduleDecoratorFn