tls: make state progression monotonic

In TLS 1.2 and 1.3 the Finished message precedes the application
data on both directions. The DATA milestone write is keyed on the
parsed certificate subjects and runs on every record, so the first
record after the handshake - for a session that ends with a fatal
alert, the alert itself - moved the tracks backwards (client 4->3,
server 5->4). The completion states were therefore not absorbing:
the finished hook windows were transient in decryption mode, and a
keyword registered at progress >= 3 would have its eof revoked and
be suppressed by the stored CANT_MATCH flag.

The setters now only move a state forward, so post-terminal writes
are no-ops and the finished states absorb.

Ticket: #9047.

src/app-layer-ssl.c

@@ -348,24 +348,30 @@ static uint64_t SSLGetTxCnt(void *state)
 
 static void UpdateClientState(SSLState *ssl_state, enum TlsStateClient s)
 {
+    /* monotonic: a late app-data write must not move the state back */
+    if (s > ssl_state->client_state) {
 #ifdef DEBUG
-    enum TlsStateClient old = ssl_state->client_state;
+        enum TlsStateClient old = ssl_state->client_state;
 #endif
-    ssl_state->client_state = s;
+        ssl_state->client_state = s;
 #ifdef DEBUG
-    SCLogDebug("toserver: state updated to %u from %u", s, old);
+        SCLogDebug("toserver: state updated to %u from %u", s, old);
 #endif
+    }
 }
 
 static void UpdateServerState(SSLState *ssl_state, enum TlsStateServer s)
 {
+    /* monotonic: a late app-data write must not move the state back */
+    if (s > ssl_state->server_state) {
 #ifdef DEBUG
-    enum TlsStateServer old = ssl_state->server_state;
+        enum TlsStateServer old = ssl_state->server_state;
 #endif
-    ssl_state->server_state = s;
+        ssl_state->server_state = s;
 #ifdef DEBUG
-    SCLogDebug("toclient: state updated to %u from %u", s, old);
+        SCLogDebug("toclient: state updated to %u from %u", s, old);
 #endif
+    }
 }
 
 static int SSLGetAlstateProgress(void *tx, uint8_t direction)