Integration with CLB emulator and bet-ref example

[euonymos]

This PR is done as the main part of Milestone 5 of the Catalyst project PSM(CLB).

List of features:

• brings up CLB emulator
• bump Ogmios
• fix era summary parsing
• bet-ref example
• update docs on testnet testing

@errfrom I am not sure we have to merge this into CTL in the long-term perspective as we discussed we want to continue further splitting it up into smaller pieces. This way I think the whole testnet suite should be a separate package.

Regarding the original testnet tests - as CHANGELOG.md says some are red. They are out of the scope, but I would like to figure out what is wrong there if I have a couple of spare hours.

Pre-review checklist

• All code has been formatted using our config (make format)
• Any new API features or modification of existing behavior are covered with tests
• The template (templates/ctl-scaffold) has been updated
• The changelog has been updated under the ## Unreleased header, using the appropriate sub-headings (### Added, ### Changed, ### Removed, ### Fixed), and the links to the appropriate issues/PRs have been included