Add support for named `slog` loggers

[AlekSi]

What should be done?

Zap logger had support for named loggers:

2024-07-10T17:10:31.882+0400  INFO  telemetry  telemetry/telemetry.go:120  Telemetry enabled.

Our current console slog output looks like that

2024-07-10T17:13:33.817+0400  INFO  telemetry/telemetry.go:120  Telemetry enabled.  {"name":"telemetry"}

We probably should add a special handling for named loggers. Things to consider:

1. Move logger name to where it was in the console output.
2. Check group handling. Use a very special field key for that?
3. Do we need chained names / loggers?

TBD