* Switch to new rocksdb with some hacks to resolve linking errors

Rocksdb and `wasmtime-environ` both link `zstd`. In the final link step,
this leads to linking errors because of duplicate symbols. The linked
Rocksdb fixes this by using `zstd-sys` as well. However, this currently
also requires modifications in `zstd-sys`. Someone will need to come up
with a better implementation.

* Switch to new version of kvdb-rocksdb

* Update client/db/src/utils.rs

Co-Authored-By: Shawn Tabrizi <[email protected]>

* Pass Extensions instead of individual objects.

* Move TransactionPool to a separate ExternalitiesExtension.

* Fix compilation.?

* Clean up.

* Refactor testing utilities.

* Add docs, fix tests.

* Fix doctest.

* Fix formatting and add some logs.

* Add some docs.

* Remove unused files.

* Adding first rough ouline of the repository structure

* Remove old CI stuff

* add title

* formatting fixes

* move node-exits job's script to scripts dir

* Move docs into subdir

* move to bin

* move maintainence scripts, configs and helpers into its own dir

* add .local to ignore

* move core->client

* start up 'test' area

* move test client

* move test runtime

* make test move compile

* Add dependencies rule enforcement.

* Fix indexing.

* Update docs to reflect latest changes

* Moving /srml->/paint

* update docs

* move client/sr-* -> primitives/

* clean old readme

* remove old broken code in rhd

* update lock

* Step 1.

* starting to untangle client

* Fix after merge.

* start splitting out client interfaces

* move children and blockchain interfaces

* Move trie and state-machine to primitives.

* Fix WASM builds.

* fixing broken imports

* more interfac...