Optional headers for wasm

[akshaybabloo]

Feature request

It would be nice to have a check box to enable wasm headers. I am not sure if this is particular for flutter, which suggests https://docs.flutter.dev/platform-integration/web/wasm#serve-the-output-with-an-http-server

Feature description

Create a check box that adds a block of custom directive with required headers, something like:

location / {
    add_header Cross-Origin-Embedder-Policy "credentialless"
    add_header Cross-Origin-Opener-Policy "same-origin"
}

How the feature is useful

Enables use of wasm when correct headers are sent