The main motivation of this commit is to add a `page.Page` interface to replace the very file-oriented `hugolib.Page` struct.
This is all a preparation step for issue #5074, "pages from other data sources".
But this also fixes a set of annoying limitations, especially related to custom output formats, and shortcodes.
Most notable changes:
* The inner content of shortcodes using the `{{%` as the outer-most delimiter will now be sent to the content renderer, e.g. Blackfriday.
This means that any markdown will partake in the global ToC and footnote context etc.
* The Custom Output formats are now "fully virtualized". This removes many of the current limitations.
* The taxonomy list type now has a reference to the `Page` object.
This improves the taxonomy template `.Title` situation and make common template constructs much simpler.
See #5074Fixes#5763Fixes#5758Fixes#5090Fixes#5204Fixes#4695Fixes#5607Fixes#5707Fixes#5719Fixes#3113Fixes#5706Fixes#5767Fixes#5723Fixes#5769Fixes#5770Fixes#5771Fixes#5759Fixes#5776Fixes#5777Fixes#5778
Note that this looks like overkill for just the logger, and that is correct,
but this will make sense once we start with the template handling etc.
Updates #2701
Many minor fixes to make test logs more consistent and correct a
mispelling.
Standardize on "[%i] got X but expected Y" for log messages. Using
a consistent layout makes it easier to read the test results. This
was mostly changing "Got" to "got". Swapped the order of values on
several calls to bring them in line with the convention.
A few log messages had a sequence number added to identify the
exact scenario that failed. Otherwise, there would be no way to
ascertain which failed When there are many scenarios.
Correct spelling of "expected."
Fixes#1028
Merged be2097e1ad
[close#1040]
