* A few missing emojies

* P2p message emojis

* Add a bit of colour

* format

* Introduce a couple of spaces

* Some spaces

* Check for url validity when creating TelemetryEndpoints

* Update code that used TelemetryEndpoints::new()

* Update commennts that referred to TelemetryEndpoints::new()

* Add tests for telemetry

* Fix typo and fix code in docs

* Return error on failing to override telemetry

* Use expect instead of suppressing errors on must-be-valid telemetry endpoints

* Update telemetry unit tests to use expect instead of unwrap

* Implement custom deserializer for TelemetryEndpoints

* Fix typo

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* minor fixes to CLI arg docs

* Update client/cli/src/params/shared_params.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* ChainSpec trait

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

* Added docs

* Fixed build

* Fixed build

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Use CLI to configure max instances cache

* Fix tests

* Move default value into CLI

* Use SmallVec

* Apply review comments

* Get rid of `SmallVec`

Co-authored-by: Bastian Köcher <git@kchr.de>

The only up-to-date deployment of PolkadotJS apps is currently on https://polkadot.js.org/apps/.
https://substrate-ui.parity.io is only useful as deliberately kept outdated version of Apps, to be used for projects still on Substrate 1.0
It cannot be used with the up-to-date chains running the Substrate 2.0 codebase, and probably won't be maintained much longer.

* Add a few metrics to Client

* Improve PrometheusConfig

* Fix client docs

Related to #4776 
Related to https://github.com/paritytech/polkadot/pull/832

To summarize the changes:
1. I did not manage to validate with types the service's Configuration. But I did reduce the possibility of errors by moving all the "fill" functions to their respective structopts
2. I split params.rs to multiple modules: one module params for just CLI parameters and one module commands for CLI subcommands (and RunCmd). Every command and params are in their own file so things are grouped better together and easier to remove
3. I removed the run and run_subcommand helpers as they are not helping much anymore. Running a command is always a set of 3 commands: 1. init 2. update config 3. run. This still allow the user to change the config before arguments get parsed or right after.
4. I added tests for all subcommands.
5. [deleted]

Overall the aim is to improve the situation with the Configuration and the optional parameters, add tests, make the API more consistent and simpler.