[gatsby-plugin-manifest] Buggy output (manifest file and images)

[pikeas]

Description

1. gatsby-plugin-manifest fails to create images when paths are different.
2. gatsby-plugin-manifest does not delete the include_favicon option when creating the manifest file.

Steps to reproduce

# gatsby-config.js
module.exports = {
  ...
  plugins: [
    ...
    {
      resolve: `gatsby-plugin-manifest`,
      options: {
        name: `foo`,
        short_name: `bar`,
        start_url: `/?utm_source=homescreen`,
        background_color: `#111111`,
        display: `minimal-ui`,
        icon: `src/images/gatsby-icon.png`,
        include_favicon: false,
        legacy: false,
        theme_color_in_head: false,
        icons: [
          {
            src: `favicon.ico`,
            sizes: `32x32`,
            type: `image/ico`,
          },
          {
            src: `icons/icon-192x192.png`,
            sizes: `192x192`,
            type: `image/png`,
          },
        ],
      },
    },
    ...
  ],
}

$ rm -rf public && gatsby build
...
Generating image thumbnails [==============================] 6/6 0.3 secs 100%
error Plugin gatsby-plugin-manifest returned an error

  Error: vips__file_open_write: unable to open file "public/icons/icon-192x192.png" for writing
  unix error: No such file or directory

This happens because of https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-manifest/src/gatsby-node.js#L72-L73

For the include_favicon issue, this is because that option is not listed at https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-manifest/src/gatsby-node.js#L46-L55

Expected result

1. The plugin should create the images.
2. The option should not be present in the final output.

Actual result

See description.

Environment

System:
OS: macOS 10.14.2
Shell: 3.0.2 - /usr/local/bin/fish
Binaries:
Node: 10.15.3 - ~/.asdf/installs/nodejs/10.15.3/bin/node
npmPackages:
gatsby: ^2.3.3 => 2.3.3
gatsby-image: ^2.0.35 => 2.0.35
gatsby-plugin-manifest: ^2.0.26 => 2.0.26
gatsby-plugin-offline: ^2.0.25 => 2.0.25
gatsby-plugin-postcss: ^2.0.7 => 2.0.7
gatsby-plugin-react-helmet: ^3.0.11 => 3.0.11
gatsby-plugin-sharp: ^2.0.32 => 2.0.32
gatsby-source-filesystem: ^2.0.28 => 2.0.28
gatsby-transformer-sharp: ^2.1.17 => 2.1.17
npmGlobalPackages:
gatsby-cli: 2.5.4

[pieh]

Would you be interested in opening PR with fixes?

For the first issue seems like we need to iterate over icons array and not rely on all icons being set to be in same directory and the second one you spot-on identified.

[pikeas]

@pieh I'm more of a Python dev than a JS dev so filing a full bug report and including the relevant lines is about the extent of how I can help. :-)

[pieh]

That's fair ;) Thanks for helping identify faulty code that cause those bugs!

[me4502]

I can put up a PR for this - I just noticed the include_favicon issue in my codebase

[me4502]

#13059 made one