[FL-2957] Unified Info API, App Error, Data Xchange (#1998)

* Update protobuf definitions
* Add Property subsystem entry point function
* Key-based system info and power info function stubs
* Remove unneeded functions
* Working power info
* Working system info
* Replace #defines with string literals
* Remove unneeded field
* Simplify system info formatting
* Refactor output callback handling
* Handle the last info element correctly
* Optimise power info, rename methods
* Add comments
* Add power debug
* Remove unneeded definitions
* Rename some files and functions
* Update protobuf definitions
* Implement App GetError and DataExchange APIs
* Send GetErrorReply with correct command_id
* Add RPC debug app stub
* Add more scenes
* Add warning, increase stack size
* Add receive data exchange scene
* Improve data exchange
* Add notifications
* Update application requirements
* Bump format version for property-based infos
* Correctly reset error text
* RCP: sync protobuf repo to latest release tag

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>

lib/toolbox/property.c

@@ -0,0 +1,33 @@
+#include "property.h"
+
+#include <core/check.h>
+
+void property_value_out(PropertyValueContext* ctx, const char* fmt, unsigned int nparts, ...) {
+    furi_assert(ctx);
+    furi_string_reset(ctx->key);
+
+    va_list args;
+    va_start(args, nparts);
+
+    for(size_t i = 0; i < nparts; ++i) {
+        const char* keypart = va_arg(args, const char*);
+        furi_string_cat(ctx->key, keypart);
+        if(i < nparts - 1) {
+            furi_string_push_back(ctx->key, ctx->sep);
+        }
+    }
+
+    const char* value_str;
+
+    if(fmt) {
+        furi_string_vprintf(ctx->value, fmt, args);
+        value_str = furi_string_get_cstr(ctx->value);
+    } else {
+        // C string passthrough (no formatting)
+        value_str = va_arg(args, const char*);
+    }
+
+    va_end(args);
+
+    ctx->out(furi_string_get_cstr(ctx->key), value_str, ctx->last, ctx->context);
+}

lib/toolbox/property.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <core/string.h>
+
+/** Callback type called every time another key-value pair of device information is ready
+ *
+ * @param      key[in]      device information type identifier
+ * @param      value[in]    device information value
+ * @param      last[in]     whether the passed key-value pair is the last one
+ * @param      context[in]  to pass to callback
+ */
+typedef void (*PropertyValueCallback)(const char* key, const char* value, bool last, void* context);
+
+typedef struct {
+    FuriString* key; /**< key string buffer, must be initialised before use */
+    FuriString* value; /**< value string buffer, must be initialised before use */
+    PropertyValueCallback out; /**< output callback function */
+    char sep; /**< separator character between key parts */
+    bool last; /**< flag to indicate last element */
+    void* context; /**< user-defined context, passed through to out callback */
+} PropertyValueContext;
+
+/** Builds key and value strings and outputs them via a callback function
+ *
+ * @param       ctx[in]     local property context
+ * @param       fmt[in]     value format, set to NULL to bypass formatting
+ * @param       nparts[in]  number of key parts (separated by character)
+ * @param       ...[in]     list of key parts followed by value
+ */
+void property_value_out(PropertyValueContext* ctx, const char* fmt, unsigned int nparts, ...);
+
+#ifdef __cplusplus
+}
+#endif