Merge 'sstables/mx/writer: handle non-full prefix row keys' from Botond Dénes

Although valid for compact tables, non-full (or empty) clustering key prefixes are not handled for row keys when writing sstables. Only the present components are written, consequently if the key is empty, it is omitted entirely.
When parsing sstables, the parsing code unconditionally parses a full prefix.
This mis-match results in parsing failures, as the parser parses part of the row content as a key resulting in a garbage key and subsequent mis-parsing of the row content and maybe even subsequent partitions.

Introduce a new system table: `system.corrupt_data` and infrastructure similar to `large_data_handler`: `corrupt_data_handler` which abstracts how corrupt data is handled. The sstable writer now passes rows such corrupt keys to the corrupt data handler. This way, we avoid corrupting the sstables beyond parsing and the rows are also kept around in system.corrupt_data for later inspection and possible recovery.

Add a full-stack test which checks that rows with bad keys are correctly handled.

Fixes: https://github.com/scylladb/scylladb/issues/24489

The bug is present in all versions, has to be backported to all supported versions.

Closes scylladb/scylladb#24492

* github.com:scylladb/scylladb:
  test/boost/sstable_datafile_test: add test for corrupt data
  sstables/mx/writer: handler rows with empty keys
  test/lib/cql_assertions: introduce columns_assertions
  sstables: add corrupt_data_handler to sstables::sstables
  tools/scylla-sstable: make large_data_handler a local
  db: introduce corrupt_data_handler
  mutation: introduce frozen_mutation_fragment_v2
  mutation/mutation_partition_view: read_{clustering,static}_row(): return row type
  mutation/mutation_partition_view: extract de-ser of {clustering,static} row
  idl-compiler.py: generate skip() definition for enums serializers
  idl: extract full_position.idl from position_in_partition.idl
  db/system_keyspace: add apply_mutation()
  db/system_keyspace: introduce the corrupt_data table

docs/dev/system_keyspace.md

@@ -121,6 +121,29 @@ SELECT * FROM system.large_cells;
 SELECT * FROM system.large_cells WHERE keyspace_name = 'ks1' and table_name = 'standard1';
 ~~~
 
+## system.corrupt\_data
+
+Stores data found to be corrupt during internal operations. This data cannot be written to sstables because then it will be spread around by repair and compaction. It will also possibly cause failures in sstable parsing.
+At the same time, the data should be kept around so that it can be inspected and possibly restored by the database operator.
+This table is used to store such data. Data is saved at the mutation-fragment level.
+
+Schema:
+```cql
+CREATE TABLE system.corrupt_data (
+    keyspace_name text,              # keyspace name of source table
+    table_name text,                 # table name of source table
+    id timeuuid,                     # id of the corrupt mutation fragment, assigned by the database when the corrupt data entry is created
+    partition_key blob,              # partition key of partition in the source table, can be incomplete or null due to corruption
+    clustering_key text,             # clustering key of mutation-fragment in the source table, can be null for some mutation-fragment kinds, can be incomplete or null due to corruption
+    mutation_fragment_kind text,     # kind of the mutation fragment, one of 'partition start', 'partition end', 'static row', 'clustering row', 'range tombstone change'; only the latter two can have clustering_key set
+    frozen_mutation_fragment blob,   # the serialized mutation fragment itself
+    origin text,                     # the name of the process that found the corruption, e.g. 'sstable-writer'
+    sstable_name text,               # the name of the sstable that contains the corrupt data, if known; sstable is not kept around, it could be compacted or deleted
+    PRIMARY KEY ((keyspace_name, table_name), id)
+) WITH CLUSTERING ORDER BY (id ASC)
+    AND gc_grace_seconds = 0;
+```
+
 ## system.raft
 
 Holds information about Raft