[AppStream] Adding <filename> to <artifact>?

[Richard Hughes]

Hi all,

I've just switched the LVFS from the nonstandard:

      <release version="1.2.5">
        <location>ipfs://QmfHhw3LewHVFi13f839yXWsBG8UHu1AaAvWQcSAVjHUXn</location>
        <checksum type="sha1"
filename="9a4e77009da7d3b5f15a1388afeb9e5d41a5a8ae-hughski-colorhug2-1.2.5.cab"
target="container">3831532bc94e6385807372a5485a8cbf6b024eeb</checksum>
        <checksum type="sha256"
filename="9a4e77009da7d3b5f15a1388afeb9e5d41a5a8ae-hughski-colorhug2-1.2.5.cab"
target="container">23d4d2c24876d2060ac4d654032d38074ff7af6eaa505f4e62a760b6fb406614</checksum>
        <url type="source">https://github.com/hughski/colorhug2-firmware</url>
        <size type="installed">16384</size>
        <size type="download">10673</size>
      </release>

to the more standard:

    <releases>
      <release version="1.2.5">
        <artifacts>
          <artifact>
            <location>ipfs://QmfHhw3LewHVFi13f839yXWsBG8UHu1AaAvWQcSAVjHUXn</location>
            <checksum
type="sha1">3831532bc94e6385807372a5485a8cbf6b024eeb</checksum>
            <checksum
type="sha256">23d4d2c24876d2060ac4d654032d38074ff7af6eaa505f4e62a760b6fb406614</checksum>
            <size type="installed">16384</size>
            <size type="download">10673</size>
          </artifact>
        </artifacts>
      </release>

This is pretty complete; although missing one bit of data. When we use
the <location> with <artifact> we don't actually now know the filename
to use for the download or disk cache -- which I snuck into the
<checksum> before. What about something like
<filename>9a4e77009da7d3b5f15a1388afeb9e5d41a5a8ae-hughski-colorhug2-1.2.5.cab</filename>
as a child of the <artifact> element?

I didn't want to do anything nonstandard, given all this migration
pain is because I did this nonstandard thing all those years ago :)

Richard.