[FL-2627] Flipper applications: SDK, build and debug system (#1387)

* Added support for running applications from SD card (FAPs - Flipper Application Packages)
* Added plugin_dist target for fbt to build FAPs
* All apps of type FlipperAppType.EXTERNAL and FlipperAppType.PLUGIN are built as FAPs by default
* Updated VSCode configuration for new fbt features - re-deploy stock configuration to use them
* Added debugging support for FAPs with fbt debug & VSCode
* Added public firmware API with automated versioning

Co-authored-by: hedger <hedger@users.noreply.github.com>
Co-authored-by: SG <who.just.the.doctor@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

applications/main/fap_loader/elf_cpp/elf_hashtable_entry.h

@@ -0,0 +1,41 @@
+#pragma once
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct sym_entry {
+    uint32_t hash;
+    uint32_t address;
+};
+
+#ifdef __cplusplus
+}
+
+#include <array>
+#include <algorithm>
+
+#define API_METHOD(x, ret_type, args_type)                                                     \
+    sym_entry {                                                                                \
+        .hash = elf_gnu_hash(#x), .address = (uint32_t)(static_cast<ret_type(*) args_type>(x)) \
+    }
+
+#define API_VARIABLE(x, var_type)                              \
+    sym_entry {                                                \
+        .hash = elf_gnu_hash(#x), .address = (uint32_t)(&(x)), \
+    }
+
+constexpr bool operator<(const sym_entry& k1, const sym_entry& k2) {
+    return k1.hash < k2.hash;
+}
+
+constexpr uint32_t elf_gnu_hash(const char* s) {
+    uint32_t h = 0x1505;
+    for(unsigned char c = *s; c != '\0'; c = *++s) {
+        h = (h << 5) + h + c;
+    }
+    return h;
+}
+
+#endif