Import test source from XReader[1].  This is not as useful as it might
seem as it's not a unit test, but it's still nice to have an easy way
to manually test this code, and reduces differences with XReader,
especially in the Meson build system.

[1] https://github.com/linuxmint/xreader/blob/master/backend/comics/test-ev-archive.c

Signed-off-by: Oz Tiram <oz.tiram@gmail.com>

Mostly copy and paste from linuxmint/xreader

Signed-off-by: Oz Tiram <oz.tiram@gmail.com>

This commit eliminates the use of external commands for opening
comic documents, and uses libarchive instead.

Fixes the warnings:

backend/comics/comics-document.c:767:21: style: Condition 'bytes<=0' is always true [knownConditionTrueFalse]

backend/epub/minizip/unzip.c:603:25: style: Condition 'unz_copyright[0]!=' '' is always false [knownConditionTrueFalse]

properties/ev-properties-view.c:197:33: style: Condition 'text' is always true [knownConditionTrueFalse]

shell/ev-sidebar-thumbnails.c:598:7: style: Condition '!loading_icon' is always true [knownConditionTrueFalse]

shell/main.c:115:6: style: Condition '!error' is always true [knownConditionTrueFalse]