vlib: add a new dl.loader module, to simplify dynamic library loading, when the DLLs may be in multiple customisable locations (#17161)

vlib/dl/loader/README.md

@@ -0,0 +1,36 @@
+## Description:
+
+`dl.loader` is an abstraction layer over `dl` that provides a more user-friendly API in the V way.
+It can be used to Dynamically Load a library during runtime in scenarios where the library to load
+does not have a determined path an can be located in different places.
+
+It also provides a way to load a library from a specific path, or from a list of paths, or from
+a custom environment variable that contains a list of paths.
+
+## Usage:
+
+```v
+import dl.loader
+
+// Load a library from a list of paths
+const default_paths = [
+	'not-existing-dynamic-link-library'
+	// 'C:\\Windows\\System32\\shell32.dll',
+	'shell32',
+]
+
+fn main() {
+	mut dl_loader := loader.get_or_create_dynamic_lib_loader(
+		key: 'LibExample'
+		env_path: 'LIB_PATH'
+		paths: default_paths
+	)!
+
+	defer {
+		dl_loader.unregister()
+	}
+
+	sym := dl_loader.get_sym('CommandLineToArgvW')!
+	assert !isnil(sym)
+}
+```