Client config - unique maps

[pileks]

Closes #1283

This PR aims to change the envs and interfaces collections inside CoreClientConfig into readonly unique maps/map-like structures.

It achieves this by introducing the concept of UriMaps:

class UriMap<TValue>
  implements Map<Uri, TValue>, ReadonlyUriMap<TValue> {
//...
}

export type ReadonlyUriMap<T> = ReadonlyMap<Uri, T>;

envs is now essentially:

  readonly envs?: ReadonlyUriMap<WrapperEnv>;

interfaces is now essentially:

  readonly interfaces?: ReadonlyUriMap<readonly Uri[]>;

Everything that can be is marked as readonly in order to relay the intended readonly nature of the CoreClientConfig.

All of this boils down to the fact that the way we instantiate a new CoreClientConfig now looks like this:

const config: CoreClientConfig = {
  resolver: ...,
  envs: new ReadonlyUriMap<WrapperEnv>([
    [
      new Uri("wrap://someuri"),
      {
        //env
      }
    ],
    [
      new Uri("wrap://someuri2"),
      {
        //env2
      }
    ],
  ]),
  interfaces: new ReadonlyUriMap<Uri[]>([
    [
      new Uri("wrap://someuri"),
      [
        new Uri("wrap://someimpl1"),
        new Uri("wrap://someimpl2"),
        new Uri("wrap://someimpl3"),
      ]
    ],
    [
      new Uri("wrap://someuri2"),
      [
        new Uri("wrap://someimpl1"),
        new Uri("wrap://someimpl2"),
        new Uri("wrap://someimpl3"),
      ]
    ]
  ])
};

[Niraj-Kamdar]

This is a really good improvement over existing list of objects structure!

[dOrgJelli]

Super nice 👏