Bump version number to 1.23.0 (#1863)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.23.0

Result:

The version in the default user-agent string will match the released
version.

Update Version.swift (#1846)

Bump version number to 1.21.1 (#1798)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.21.1

Result:

The version in the default user-agent string will match the released
version.

Bump version number to 1.21.0 (#1741)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.21.0

Result:

The version in the default user-agent string will match the released
version.

Additional keepalive diagnostics (#1692)

Motivation:

It's useful to know the state of keepalive when debugging connection
issues. gRPC doesn't emit any logs around this at the moment which makes
debugging difficult.

Modifications:

Add additional logs to the idle handler when:
- the idle timeout task is scheduled, cancelled, and fires
- the keepalive timer is scheduled
- the scheduled close timer is fired
- the connection is closed
- GOAWAY frames are sent (already logs on receive)
- PING frames are sent and received

Result:

Better visibility into connection lifecycle

Bump version number to 1.19.1 (#1642)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.19.1

Result:

The version in the default user-agent string will match the released
version.

Bump version number to 1.19.0 (#1637)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.19.0

Result:

The version in the default user-agent string will match the released
version.

Bump version to 1.18.0 (#1625)

Co-authored-by: George Barnett <[email protected]>

Bump version number to 1.17.0 (#1614)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.17.0

Result:

The version in the default user-agent string will match the released
version.

Bump version number to 1.16.0 (#1596)

Motivation:

We plan on tagging a release soon.

Modifications:

- Bump the version to 1.16.0

Result:

The version in the default user-agent string will match the released
version.