Add stubs for lzstring (#11479)

stubs/lzstring/@tests/stubtest_allowlist.txt

@@ -0,0 +1,6 @@
+# Internal implementation details that are intentionally missing from stub
+lzstring.keyStrBase64
+lzstring.keyStrUriSafe
+lzstring.baseReverseDic
+lzstring.Object
+lzstring.getBaseValue

stubs/lzstring/METADATA.toml

@@ -0,0 +1,2 @@
+version = "1.0.*"
+upstream_repository = "https://github.com/gkovacs/lz-string-python"

stubs/lzstring/lzstring/__init__.pyi

@@ -0,0 +1,17 @@
+class LZString:
+    @staticmethod
+    def compress(uncompressed: str | None) -> str: ...
+    @staticmethod
+    def compressToUTF16(uncompressed: str | None) -> str: ...
+    @staticmethod
+    def compressToBase64(uncompressed: str | None) -> str: ...
+    @staticmethod
+    def compressToEncodedURIComponent(uncompressed: str | None) -> str: ...
+    @staticmethod
+    def decompress(compressed: str | None) -> str | None: ...
+    @staticmethod
+    def decompressFromUTF16(compressed: str | None) -> str | None: ...
+    @staticmethod
+    def decompressFromBase64(compressed: str | None) -> str | None: ...
+    @staticmethod
+    def decompressFromEncodedURIComponent(compressed: str | None) -> str | None: ...