Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/CPR/include/cpr/timeout.h

@@ -0,0 +1,25 @@
+#ifndef CPR_TIMEOUT_H
+#define CPR_TIMEOUT_H
+
+#include <chrono>
+#include <cstdint>
+
+namespace cpr {
+
+class Timeout {
+  public:
+    // NOLINTNEXTLINE(google-explicit-constructor, hicpp-explicit-conversions)
+    Timeout(const std::chrono::milliseconds& duration) : ms{duration} {}
+    // NOLINTNEXTLINE(google-explicit-constructor, hicpp-explicit-conversions)
+    Timeout(const std::int32_t& milliseconds) : Timeout{std::chrono::milliseconds(milliseconds)} {}
+
+    // No way around since curl uses a long here.
+    // NOLINTNEXTLINE(google-runtime-int)
+    long Milliseconds() const;
+
+    std::chrono::milliseconds ms;
+};
+
+} // namespace cpr
+
+#endif