[FL-3174] Dolphin builder in ufbt; minor ufbt/fbt improvements (#2601)

* ufbt: added "dolphin_ext" target (expects "external" subfolder in cwd with dolphin assets); cleaned up unused code
* ufbt: codestyle fixes
* scripts: fixed style according to ruff linter
* scripts: additional cleanup & codestyle fixes
* github: pass target hw code when installing local SDK with ufbt
* ufbt: added error message for missing folder in dolphin builder
* scripts: more linter fixes
* sdk: added flipper_format_stream; ufbt: support for --extra-define
* fbt: reduced amount of global defines
* scripts, fbt: rearranged imports

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

scripts/update.py

@@ -1,16 +1,16 @@
 #!/usr/bin/env python3
 
-from flipper.app import App
-from flipper.utils.fff import FlipperFormatFile
-from flipper.assets.coprobin import CoproBinary, get_stack_type
-from flipper.assets.obdata import OptionBytesData, ObReferenceValues
-from os.path import basename, join, exists
+import math
 import os
 import shutil
-import zlib
 import tarfile
-import math
+import zlib
+from os.path import exists, join
 
+from flipper.app import App
+from flipper.assets.coprobin import CoproBinary, get_stack_type
+from flipper.assets.obdata import ObReferenceValues, OptionBytesData
+from flipper.utils.fff import FlipperFormatFile
 from slideshow import Main as SlideshowMain
 
 
@@ -267,9 +267,9 @@ class Main(App):
 
     @staticmethod
     def batch(iterable, n=1):
-        l = len(iterable)
-        for ndx in range(0, l, n):
-            yield iterable[ndx : min(ndx + n, l)]
+        iterable_len = len(iterable)
+        for ndx in range(0, iterable_len, n):
+            yield iterable[ndx : min(ndx + n, iterable_len)]
 
 
 if __name__ == "__main__":