[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>

lib/toolbox/sha256.h

@@ -1,3 +1,9 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define SHA256_DIGEST_SIZE 32
 #define SHA256_BLOCK_SIZE 64
 
@@ -12,3 +18,7 @@ void sha256_start(sha256_context* ctx);
 void sha256_finish(sha256_context* ctx, unsigned char output[32]);
 void sha256_update(sha256_context* ctx, const unsigned char* input, unsigned int ilen);
 void sha256_process(sha256_context* ctx);
+
+#ifdef __cplusplus
+}
+#endif