use aggregated client runtime generator

[kuhe]

Requires aws/aws-sdk-js-v3#4639

Switch to using an aggregated client runtime generator instead of codegen.

before

import { ACommand } from ...
import { BCommand } from ...

export class Aggregated {
  public a() {}
  public b() {} // per command class
}

after

import { ACommand } from ...
import { BCommand } from ...

const commands = {
  ACommand,
  BCommand,
}

export interface Aggregated {
  a()
  b()
}

export class Aggregated implements Aggregated {
  constructor() {
    createAggregatedClient(commands, this);
  }
}

Overall change appears to be around -2% to -3% dist-cjs.

[milesziemer]

Is there any way to avoid duplicating the logic for creating the client config and barebones client type names? Maybe String barebonesClientName = serviceSymbol.getName();. And I think serviceSymbol.getNamespace() might give you the "./src/" + aggregateClientName + "Client" part.

[milesziemer]

Maybe we should add another method in ServiceBareBonesClientGenerator for getting the config type name, like https://github.com/awslabs/smithy-typescript/blob/a526a73f8fada65c9ef0bddea94a85695229f2c4/smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/ServiceBareBonesClientGenerator.java#L90