Add global token listing

### Is your feature request related to a problem?

We would like to provide a list of the tokens created in the network for transparency, discovery purposes.
Sharded network makes complex the complete request of a network.
However, thanks to the Beacon Chain we can implement this feature easily.

### Describe the solution you'd like

During Self Repair, each node request the Beacon Chain to know which transaction it should synchronize.
The information stored in the Beacon Chain about transaction is like a header (light version) containing: tx address, tx type, tx timestamp, tx movements.
So during the self-repair, the node could ingest transaction of type `token` and fill a local database file, containing the list of tokens of the network.

After that, we can provide an API which will stream this file and announce the list of token in the network.
We can also build a UI in the explorer to list the tokens.

### Additional context

This issue can be compartmentalized into a few steps:
- [ ] Write to disk all the tokens' transaction addresses in the self-repair cycle
- [ ] Create an API to read this file
- [ ] Create a UI to list all the tokens

Start by tracing the self-repair cycle and how nodes read transaction headers from the Beacon Chain. The proposed work covers writing token transaction addresses to a local file, exposing an API to read it, and listing the tokens in the explorer UI. Done means all three checklist steps are implemented and the network token list is available.

Written by the indexing model from the issue text.