Approval Checking Improvements Omnibus (#2480)

* add tracing to approval voting

* notify if session info is not working

* add dispute period to chain specs

* propagate genesis session to parachains runtime

* use `on_genesis_session`

* protect against zero cores in computation

* tweak voting rule to be based off of best and add logs

* genesis configuration should use VRF slots only

* swallow more keystore errors

* add some docs

* make validation-worker args non-optional and update clap

* better tracing for bitfield signing and provisioner

* pass amount of bits in bitfields to inclusion instead of recomputing

* debug -> warn for some logs

* better tracing for availability recovery

* a little av-store tracing

* bridge: forward availability recovery messages

* add missing try_from impl

* some more tracing

* improve approval distribution tracing

* guide: hold onto pending approval messages until NewBlocks

* Hold onto pending approval messages until NewBlocks

* guide: adjust comment

* process all actions for one wakeup at a time

* vec

* fix network bridge test

* replace randomness-collective-flip with Babe

* remove PairNotFound

polkadot/cli/src/cli.rs

@@ -60,8 +60,8 @@ pub enum Subcommand {
 #[allow(missing_docs)]
 #[derive(Debug, StructOpt)]
 pub struct ValidationWorkerCommand {
-	/// The path that the executor can use for it's caching purposes.
-	pub cache_base_path: Option<std::path::PathBuf>,
+	/// The path that the executor can use for its caching purposes.
+	pub cache_base_path: std::path::PathBuf,
 
 	#[allow(missing_docs)]
 	pub mem_id: String,