Add lighthouse db command (#3129)

## Proposed Changes

Add a `lighthouse db` command with three initial subcommands:

- `lighthouse db version`: print the database schema version.
- `lighthouse db migrate --to N`: manually upgrade (or downgrade!) the database to a different version.
- `lighthouse db inspect --column C`: log the key and size in bytes of every value in a given `DBColumn`.

This PR lays the groundwork for other changes, namely:

- Mark's fast-deposit sync (https://github.com/sigp/lighthouse/pull/2915), for which I think we should implement a database downgrade (from v9 to v8).
- My `tree-states` work, which already implements a downgrade (v10 to v8).
- Standalone purge commands like `lighthouse db purge-dht` per https://github.com/sigp/lighthouse/issues/2824.

## Additional Info

I updated the `strum` crate to 0.24.0, which necessitated some changes in the network code to remove calls to deprecated methods.

Thanks to @winksaville for the motivation, and implementation work that I used as a source of inspiration (https://github.com/sigp/lighthouse/pull/2685).

beacon_node/network/src/sync/block_lookups/mod.rs

@@ -8,7 +8,6 @@ use lru_cache::LRUCache;
 use slog::{crit, debug, error, trace, warn, Logger};
 use smallvec::SmallVec;
 use store::{Hash256, SignedBeaconBlock};
-use strum::AsStaticRef;
 use tokio::sync::mpsc;
 
 use crate::beacon_processor::{ChainSegmentProcessId, WorkEvent};
@@ -176,7 +175,7 @@ impl<T: BeaconChainTypes> BlockLookups<T> {
                 // request finished correctly, it will be removed after the block is processed.
             }
             Err(error) => {
-                let msg: &str = error.as_static();
+                let msg: &str = error.into();
                 cx.report_peer(peer_id, PeerAction::LowToleranceError, msg);
                 // Remove the request, if it can be retried it will be added with a new id.
                 let mut req = request.remove();
@@ -243,7 +242,7 @@ impl<T: BeaconChainTypes> BlockLookups<T> {
                 VerifyError::RootMismatch
                 | VerifyError::NoBlockReturned
                 | VerifyError::ExtraBlocksReturned => {
-                    let e = e.as_static();
+                    let e = e.into();
                     warn!(self.log, "Peer sent invalid response to parent request.";
                         "peer_id" => %peer_id, "reason" => e);
 
@@ -310,8 +309,13 @@ impl<T: BeaconChainTypes> BlockLookups<T> {
                     }
                 }
                 Err(e) => {
-                    trace!(self.log, "Single block request failed on peer disconnection";
-                        "block_root" => %req.hash, "peer_id" => %peer_id, "reason" => e.as_static());
+                    trace!(
+                        self.log,
+                        "Single block request failed on peer disconnection";
+                        "block_root" => %req.hash,
+                        "peer_id" => %peer_id,
+                        "reason" => <&str>::from(e),
+                    );
                 }
             }
         }

beacon_node/network/src/sync/block_lookups/parent_lookup.rs

@@ -1,6 +1,6 @@
 use lighthouse_network::PeerId;
 use store::{EthSpec, Hash256, SignedBeaconBlock};
-use strum::AsStaticStr;
+use strum::IntoStaticStr;
 
 use crate::sync::{
     manager::{Id, SLOT_IMPORT_TOLERANCE},
@@ -28,7 +28,7 @@ pub(crate) struct ParentLookup<T: EthSpec> {
     current_parent_request_id: Option<Id>,
 }
 
-#[derive(Debug, PartialEq, Eq, AsStaticStr)]
+#[derive(Debug, PartialEq, Eq, IntoStaticStr)]
 pub enum VerifyError {
     RootMismatch,
     NoBlockReturned,

beacon_node/network/src/sync/block_lookups/single_block_lookup.rs

@@ -4,7 +4,7 @@ use lighthouse_network::{rpc::BlocksByRootRequest, PeerId};
 use rand::seq::IteratorRandom;
 use ssz_types::VariableList;
 use store::{EthSpec, Hash256, SignedBeaconBlock};
-use strum::AsStaticStr;
+use strum::IntoStaticStr;
 
 /// Object representing a single block lookup request.
 #[derive(PartialEq, Eq)]
@@ -28,14 +28,14 @@ pub enum State {
     Processing { peer_id: PeerId },
 }
 
-#[derive(Debug, PartialEq, Eq, AsStaticStr)]
+#[derive(Debug, PartialEq, Eq, IntoStaticStr)]
 pub enum VerifyError {
     RootMismatch,
     NoBlockReturned,
     ExtraBlocksReturned,
 }
 
-#[derive(Debug, PartialEq, Eq, AsStaticStr)]
+#[derive(Debug, PartialEq, Eq, IntoStaticStr)]
 pub enum LookupRequestError {
     TooManyAttempts,
     NoPeers,