HTML5: Enable mbedTLS module for Crypto object

Increases the size of the wasm by around 3% (~300-350 KiB).

This enables using the Crypto object for hashing, signing and encryption,
and therefore reduces the gap between the features of the HTML5 platform
and other platforms.

Closes https://github.com/godotengine/godot-proposals/issues/3574.

(cherry picked from commit 3ff6d794c0)

doc/classes/CryptoKey.xml

@@ -6,7 +6,6 @@
 	<description>
 		The CryptoKey class represents a cryptographic key. Keys can be loaded and saved like any other [Resource].
 		They can be used to generate a self-signed [X509Certificate] via [method Crypto.generate_self_signed_certificate] and as private key in [method StreamPeerSSL.accept_stream] along with the appropriate certificate.
-		[b]Note:[/b] Not available in HTML5 exports.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/HashingContext.xml

@@ -27,7 +27,6 @@
 		    # Print the result as hex string and array.
 		    printt(res.hex_encode(), Array(res))
 		[/codeblock]
-		[b]Note:[/b] Not available in HTML5 exports.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/X509Certificate.xml

@@ -6,7 +6,6 @@
 	<description>
 		The X509Certificate class represents an X509 certificate. Certificates can be loaded and saved like any other [Resource].
 		They can be used as the server certificate in [method StreamPeerSSL.accept_stream] (along with the proper [CryptoKey]), and to specify the only certificate that should be accepted when connecting to an SSL server via [method StreamPeerSSL.connect_to_stream].
-		[b]Note:[/b] Not available in HTML5 exports.
 	</description>
 	<tutorials>
 	</tutorials>

platform/javascript/detect.py

@@ -48,11 +48,6 @@ def get_flags():
     return [
         ("tools", False),
         ("builtin_pcre2_with_jit", False),
-        # Disabling the mbedtls module reduces file size.
-        # The module has little use due to the limited networking functionality
-        # in this platform. For the available networking methods, the browser
-        # manages TLS.
-        ("module_mbedtls_enabled", False),
     ]