Inital native code for verified mod auto-downloading (#545)

Allows client to download a mod archive from the Thunderstore API, and extract included mods in the remote mods folder of the current game profile.

Not all mods can be automatically downloaded, as it would cause some security issues, and Thunderstore mod name cannot be deduced from actual mod name: to be eligible to auto-downloading, a mod must appear in the list of verified mods.

Said list and complete mod verification procedure are described here: https://github.com/R2Northstar/VerifiedMods

Exposes two commands to test the feature:
- `fetch_verified_mods` retrieves verified mods list from the GitHub organization, and stores it locally;
- `download_mod` does the actual mod downloading/extraction job.

.gitmodules

@@ -6,3 +6,6 @@
 	path = thirdparty/minhook
 	url = https://github.com/TsudaKageyu/minhook
 	ignore = untracked
+[submodule "thirdparty/minizip"]
+	path = thirdparty/minizip
+	url = https://github.com/zlib-ng/minizip-ng.git

NorthstarDLL/CMakeLists.txt

@@ -2,6 +2,7 @@
 
 find_package(minhook REQUIRED)
 find_package(libcurl REQUIRED)
+find_package(minizip REQUIRED)
 
 add_library(NorthstarDLL SHARED
             "resources.rc"
@@ -73,6 +74,8 @@ add_library(NorthstarDLL SHARED
             "logging/sourceconsole.h"
             "masterserver/masterserver.cpp"
             "masterserver/masterserver.h"
+            "mods/autodownload/moddownloader.h"
+            "mods/autodownload/moddownloader.cpp"
             "mods/compiled/kb_act.cpp"
             "mods/compiled/modkeyvalues.cpp"
             "mods/compiled/modpdef.cpp"
@@ -156,6 +159,7 @@ add_library(NorthstarDLL SHARED
 target_link_libraries(NorthstarDLL PRIVATE
                       minhook
                       libcurl
+                      minizip
                       WS2_32.lib
                       Crypt32.lib
                       Cryptui.lib