fbt: lint fixes (#2008)

* lint: exclude "lib" subfolder from naming checks; fbt: moved LINT_SOURCES from literal strings to Dir() nodes
* lint: also exclude hidden directories

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

lib/SConscript

@@ -2,19 +2,19 @@ Import("env")
 
 env.Append(
     LINT_SOURCES=[
-        "lib/app-scened-template",
-        "lib/digital_signal",
-        "lib/drivers",
-        "lib/flipper_format",
-        "lib/infrared",
-        "lib/nfc",
-        "lib/one_wire",
-        "lib/ST25RFAL002",
-        "lib/subghz",
-        "lib/toolbox",
-        "lib/u8g2",
-        "lib/update_util",
-        "lib/print",
+        Dir("app-scened-template"),
+        Dir("digital_signal"),
+        Dir("drivers"),
+        Dir("flipper_format"),
+        Dir("infrared"),
+        Dir("nfc"),
+        Dir("one_wire"),
+        Dir("ST25RFAL002"),
+        Dir("subghz"),
+        Dir("toolbox"),
+        Dir("u8g2"),
+        Dir("update_util"),
+        Dir("print"),
     ],
     SDK_HEADERS=[
         File("one_wire/one_wire_host_timing.h"),