* Using unsigned types for message type and requst IDs
why:
Negative values are neither defined for RLP nor in the protocol specs
which refer to the RLPs (see yellow paper app B clause (199).
* Fix `int` argument (must be `uint`) in fuzzing tests
why:
Not part of all tests so it slipped through.
* Add build_dcli target and add it to CI
* Fix local imports for dcli
* And use local imports for all other files too
* Use local imports in tests and rlpx protocols
* use bearssl rng throughout
* seeder can fail
* imports and exports
* modules, sigh
* one more try
* move var
* even fewer thread vars
* remove out-of-date genrated files
* simplify some modules
* mark several modules with raises
* fix clearing of keys in auth.nim
* fix keyfile case dropping off
* fix keyfile stream storage
* uuid should be output in lowercase
* enode: simplify API