* Make prefixes_test.go more resilient against garbage left
by a prior crash. Also correct error logging.
* Don't do the ones' complement thing with DBStateValue fields
HistFlushCount, CompFlushCount, CompCursor. Python-herald
doesn't do it, and it presents one more irregular case for
(un)marshalling fields.
* Simplify type-specific partial packing, and simplify dispatch for pack key/value.
* Add struct field annotations and refactor to prepare for
use of "restruct" generic packing/unpacking.
* Add dynamic pack/unpack based on "restruct" module.
Dispatch normal pack/unpack through tableRegistry[] map
instead of switch.
* Add 5 new prefixes/tables (TrendingNotifications..HashXMempoolStatus).
* Undo rename. TouchedOrDeleted -> ClaimDiff.
* Fixup callers of eliminated partial pack functions. Have them use key.PartialPack(n).
* Add pluggable SerializationAPI. Use it in prefixes_test.
Populate PrefixRowKV.RawKey,RawValue when appropriate.
* Undo accidental bump of rocksdb version.
* Add .vscode dir to gitignore.
* Fix ClaimToChannelValue annotation. Implement BlockTxsValue workaround
as I can't find the right annotation to get it marshalled/unmarshalled.
* Strengthen partial packing verification. Fix bugs
in UnpackKey/UnpackValue for new types.
* Remove .DS_Store, and ignore in future.
* Fix MempoolTxKey, TouchedHashXValue. Remove some unneeded struct tags.
* Generate test data and complete the tests for the new tables.
Add Fuzz tests for TouchedHashXKey, TouchedHashXValue with
happy path test data (only).
* Move tableRegistry to prefixes.go and rename it prefixRegistry.
Other minor fixes, comments.
* Add test that runs through GetPrefixes() contents, and verifies
they are registered in prefixRegistry.
