fbt: fixes for ufbt compat (#1940)

* fbt: split sdk management code
* scripts: fixed import handling
* fbt: sdk: reformatted paths
* scrips: dist: bundling libs as a build artifact
* fbt: sdk: better path management
* typo fix
* fbt: sdk: minor path handling fixes
* toolchain: fixed windows toolchain download

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

scripts/fbt/sdk/__init__.py

@@ -0,0 +1,44 @@
+from typing import Set, ClassVar
+from dataclasses import dataclass, field
+
+
+@dataclass(frozen=True)
+class ApiEntryFunction:
+    name: str
+    returns: str
+    params: str
+
+    csv_type: ClassVar[str] = "Function"
+
+    def dictify(self):
+        return dict(name=self.name, type=self.returns, params=self.params)
+
+
+@dataclass(frozen=True)
+class ApiEntryVariable:
+    name: str
+    var_type: str
+
+    csv_type: ClassVar[str] = "Variable"
+
+    def dictify(self):
+        return dict(name=self.name, type=self.var_type, params=None)
+
+
+@dataclass(frozen=True)
+class ApiHeader:
+    name: str
+
+    csv_type: ClassVar[str] = "Header"
+
+    def dictify(self):
+        return dict(name=self.name, type=None, params=None)
+
+
+@dataclass
+class ApiEntries:
+    # These are sets, to avoid creating duplicates when we have multiple
+    # declarations with same signature
+    functions: Set[ApiEntryFunction] = field(default_factory=set)
+    variables: Set[ApiEntryVariable] = field(default_factory=set)
+    headers: Set[ApiHeader] = field(default_factory=set)