Move db-analyser and db-synthesiser to a separate repository

The `db-analyser` tool is used with chains produced with a certain version of `cardano-node` that is usually not the `master` version of this repository. Whenever we want to develop a new feature for `db-analyser` we have to develop on top of an older version of `ouroboros-network` (eg https://github.com/input-output-hk/ouroboros-network/pull/4014). Similarly, when we want to analyze the mainnet chain, we usually have to checkout an older commit of this repository, otherwise, we run into problems such as incompatible serialisation formats or ledger rules.

I'd propose to move `db-analyzer` to a different repository. Two options are:

- `cardano-node`.
- A new repository (this will involve more work setting up CI, or maybe fewer if no `nix` skills are required for this).

By doing this, the `master` version of the repository in which `db-analyser` is, will be closer to the `master` version of the node, and safe from breaking changes in the networking, consensus, and ledger layers.

This will also help reduce the surface area of consensus.