chore: isolated module set to true, exports split to export type

[ziv]

Description:

In order to be more compatible with ESM and other bundlers or TypeScript environment (Babel and Deno, for example), isolatedModules flag should be turned on.

This PR contain only this change in tsconfig and fix some build error (replace "export" with "export type" for interfaces).
Reference:
https://www.typescriptlang.org/tsconfig#isolatedModules

All tests and build pass.

[jakovljevic-mladen]

Hi @ziv, unfortunately, we already had an attempt to introduce export type syntax to the repo, but it failed due to docs app being unable to generate documentation for these types (GlobalConfig, RetryConfig and all others). Please take a look at this PR (and this comment) and the reverting PR.

I'd close this PR, but since it also includes isolatedModules: true change, I'll check with the core team how/should we include this.

[benlesh]

Closing this. It doesn't seem like this is solving any issues we're currently having. Thank you for your contribution, @ziv .