update samples to use env config to configure clients

[THardy98]

What was changed

Update samples to configure clients using envconfig package.

Why?

New standard practice for configuring clients.

Checklist

1. Closes [Feature Request] Environment configuration #421

2. How was this tested:
   Existing tests and ran a few samples that use slightly different configs (with data converter, with interceptor, etc.)

3. Any docs updates needed?
   No

[chris-olszewski]

My only concern about switching all of these to use envconfig is possible confusion when setting up an example with npx @temporalio/create and they have a system config file, it will get used as opposed to the defaults referenced in the sample READMEs.

Also, is there no benefit for keeping the comments regarding how to setup the connection for production? Maybe update it to link to envconfig profile docs/sample?

[chris-olszewski]

Are the comments no longer helpful with envconfig?

[THardy98]

Added a little comment, linking to docs

[THardy98]

My only concern about switching all of these to use envconfig is possible confusion when setting up an example with npx @temporalio/create and they have a system config file, it will get used as opposed to the defaults referenced in the sample READMEs.

That's a good point. My feeling though is that if a user has a system config file already, they know enough about the feature to be aware of this.

Also, is there no benefit for keeping the comments regarding how to setup the connection for production? Maybe update it to link to envconfig profile docs/sample?

Added a little comment that linked to the docs