[spinel] add support for logging crash dumps (#10061)

This commit adds a new feature that allows platforms to log crash logs.

### Additions
- `void otPlatLogCrashDump(void)` - API that logs a crash dump using
  OpenThread Logging APIs
- `SPINEL_PROP_RCP_LOG_CRASH_DUMP` - spinel prop that calls
  `otPlatLogCrashDump()` when `Set`
- `SPINEL_CAP_RCP_LOG_CRASH_DUMP` - spinel capability denoting that a
  RCP supports logging crash dumps

### Usage
- For `ot-cli-ftd|mtd`, `otPlatLogCrashDump()` is called at the end of
  app initialization, before the main loop. See [main.c]
- For Host/RCP setups, during initialization, the Host gets the RCP
  capabilities. If the RCP has the `SPINEL_CAP_RCP_LOG_CRASH_DUMP`
  capability, the Host will `Set` the `SPINEL_PROP_RCP_LOG_CRASH_DUMP`
  property, triggering the RCP to call `otPlatLogCrashDump()`.
  - If RCP Recovery is enabled, the this will also happen once the RCP
    has been restored

examples/apps/cli/main.c

@@ -39,6 +39,7 @@
 #include <openthread/diag.h>
 #include <openthread/tasklet.h>
 #include <openthread/platform/logging.h>
+#include <openthread/platform/misc.h>
 
 #include "openthread-system.h"
 #include "cli/cli_config.h"
@@ -140,6 +141,10 @@ pseudo_reset:
     IgnoreError(otCliSetUserCommands(kCommands, OT_ARRAY_LENGTH(kCommands), instance));
 #endif
 
+#if OPENTHREAD_CONFIG_PLATFORM_LOG_CRASH_DUMP_ENABLE
+    otPlatLogCrashDump();
+#endif
+
     while (!otSysPseudoResetWasRequested())
     {
         otTaskletsProcess(instance);