Refactor folder (#10475)

Move many third-party components' source codes from the src folder to a new folder called deps_src. The goal is to make the code structure clearer and easier to navigate.

deps_src/nanosvg/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.13)
+
+project(nanosvg)
+
+add_library(nanosvg INTERFACE)
+
+target_include_directories(nanosvg INTERFACE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+target_sources(nanosvg INTERFACE
+    ${CMAKE_CURRENT_SOURCE_DIR}/nanosvg.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/nanosvgrast.h
+)

deps_src/nanosvg/README.txt

@@ -0,0 +1 @@
+Upstream source: https://github.com/SoftFever/nanosvg