Update formatting of left column in reports

[mannodermaus]

This is a proposal to adjust the layout of Roborazzi reports a little, addressing some quirks I have found when working with it. Left is before, right is after!

General updates

I adjusted the default width of the report container to account for larger screens. Instead of materialize's default values (90%, max 1280px), it is now 95% with a maximum width of 1440px. Furthermore, the ratio between the left and right columns is now 40-60, a little different to the 30-70 from before. I also added a little fix for contextData: Before this PR, if any contextData has an empty value, then no context data would be shown at all. This is now changed so that only these empty context data entries are filtered out instead.

Show relative path to output directory above each file name

This accounts for use cases where a non-default directory is used to store images. The folder is a little smaller than the file name, too.

Fix display of contextData and make it easier to digest

First of all, fix the missing line break. Furthermore, use a little sub-table to display context data key-value pairs more neatly. Add a cute badge thingy to make this data stand out a bit more.

Fix display of aiAssertionResults

Another missing line break fix. Use a badge to separate these results from the main file name. Add some tweaks to color and size to achieve hierarchy of information.

[takahirom]

Thank you for your contribution! It looks excellent.