Reimplement the MIME body extraction and HTML rewriting from mblog in
Rust so that shelling out to it becomes viable. The problem with
mnote-html is mainly that it – being written in CL – requires a ~300MB
executable and is a bit sluggish starting.
Change-Id: I5c1adc1a7ab5f3dde207f9a1f67ace685bd3f69f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/13014
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: sterni <sternenseemann@systemli.org>
