This still requires lots of work.

This include a mostly complete compiler, (minus a few types and literals).
More nodes and scopes will be required.

Will be fine performance wise once #57 is fixed.

…nation

This include a working single threaded structure for RAPIDE.

Todo:
- Multithreading
- dontGoThere map for serverDrivenWorker
- Racing

This help avoiding situations where you go race someone else, in a shallow dag, and you get a block next to them in the traversal.

We do not have consensus nor usecase for the language part of IPSL,
to avoid long debates for some not yet usefull pieces of code,
I've removed it and we will handle merging this part seperately (or never merge it).

In 719b5e6 I changed `download.expand` to release the node lock before returning.
This allows other workers to access the just expanded node while we walk up the chain ancestry.
This mean that when we relock the node later to add it to our list of tasks, someone else may have downloaded some of the blocks already and thus they are not in the childrens slice and thus we wont add them to our list.

This also solve the case where you give a Traversal that is not supported by the underlying protocol,
in that case we want to kill the current download and retry deeper, while previously we would hard error on this and kill the worker.

This happen when duplicated blocks are part of the dag.

This fallsback to fastrand in go1.21 and is well fast enough.

It lacks many features mainly backtracking and rescan.