Lazy connectivity for Temporal client and healthCheck

Users should be able to create a Temporal Client for a temporarily unavailable Temporal server.

SDKs should have the main client or one of the clients that:

1. Don't have an eager healthCheck and getSystemInfo calls in the constructor.
2. getSystemCapabilities call should be performed on the first client call in a lazy manner.
3. healthCheck endpoint should be exposed on the Client that will allow users to perform a health check for the corresponded gRPC service. It will also allow to initialize a connection in an explicit eager manner and perform initialization activities (system capabilities negotiation right now).
4. There may be a .connect() or .dial call that establishes the connection and fetches system capabilities and which will allow to provide the same functionality/guarantees as an eager client provides.

• https://github.com/temporalio/sdk-java/issues/828
• https://github.com/temporalio/sdk-go/issues/793
• https://github.com/temporalio/sdk-typescript/issues/312
• https://github.com/temporalio/sdk-php/issues/224
• https://github.com/temporalio/sdk-python/issues/92

No files or tests are named. Start by comparing the linked SDK issues and the existing client entry points for healthCheck, getSystemInfo, and getSystemCapabilities; the work is done when lazy client creation, first-call capability negotiation, and an explicit health or connect operation are defined for the target SDK.