feat(aggregator): replace cexplorer pools ticker retriever with a blockfrost based implementation

[Alenar]

Content

This PR replace the service responsible for fetching pools ticker and name from a cexplorer based implementation to a blockfrost based one.

CExplorer removed the file from their server that was used to fetch this data, instead they now propose to use an api but it's not yet stable.
Blockfrost already propose an api endpoint, /pools/extended, that expose the data we need, plus their current api limits (50 000 requests per day / max 500 per seconds recharging at a rate of 50 each second) allow us to fetch all pools data without hitting their limit.

Note

Following discussion on this PR it have been decided to do further modification on the configuration necessitating a new Secret wrapper type, this will be done in another PR so some TODO were added.

Details

Mithril aggregator

• tools::signer_importer:
  • refactor the module:
    • promote it to a directory (from a file)
    • split it into isolated parts: api.rs for the traits and main structure definition, one dedicated file for each retriever and persister impl
    • better types scoping: rework it's exported types so they are scoped into tools::signer_importer instead of being reexported at the crate root.
  • add BlockfrostSignerRetriever, leveraging the blockfrost crate.
  • remove CExplorerSignerRetriever, as it's not working anymore there's no justification to keep it
• Configuration:
  • define BlockfrostParameters struct to hold all blockfrost related configs (:pencil2: for security blockfrost project id is not directly stored, instead a env var name were it should be fetched is given)
  • add blockfrost_parameters key
  • remove cexplorer_pools_url key
• Update Dependency injection and serve command to use the new BlockfrostSignerRetriever

Misc

• upgrade serde_json to 1.0.149 (needed by the blockfrost crate)
• mithril-cli-helper: add serde_deserialization::string_or_struct_optional to support deserialing into optional types string that contains a configuration as a json
• Update infrastructure
• Update documentation

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • CHANGELOG file is updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested
• Documentation
  • Update documentation website (if relevant)
  • No new TODOs introduced

Issue(s)

Relates to #2878

[github-actions]

Test Results

    4 files  ± 0    169 suites  ±0   22m 5s ⏱️ +5s
2 306 tests +13  2 306 ✅ +13  0 💤 ±0  0 ❌ ±0 
7 253 runs  +52  7 253 ✅ +52  0 💤 ±0  0 ❌ ±0 

Results for commit 56a682f. ± Comparison against base commit 3b3f465.

♻️ This comment has been updated with latest results.

[jpraynaud]

LGTM 👍