* Define `CHRONO_UTILITIES_TIMESPAN_INTEGER_SCALE_OVERLOADS` consistently
with all necassary changes
* Avoid ambiguity between enum members and certain class/struct names
* Allow one to get a `Popularity` where `.rating` is always between 1 and 5
via `TagValue::toScaledPopularity()` (or a "raw" scale by specifying the
corresponding tag format)
* Allow one to assign a `Popularity` with `.scale = TagType::Unspecified`
and `.rating` between 1 and 5 (or a "raw" scale by specifying the
corresponding tag format). It will then be converted internally to
the required scale (whatever the tag format internally uses)
* Ensure all tag formats with popularity/rating field use
`TagValue::toScaledPopularity()` internally when a `Popularity`
object is assigned
* Ensure all tag formats with popularity/rating field store the rating as
popularity object to preserve the scaling information
* Keep passing raw strings around working
* `TagValue::toString()` still does *no* scaling
* `TagValue::toScaledPopularity()` does *no* scaling for text values
and instead just assigns the specified scale
* See https://github.com/Martchus/tagparser/issues/23
This would allow implementing a way to convert between different scales and
which in turn would allow the UI to provide an editor with a generic scale
(e.g. stars) instead of only allowing to edit raw values as string.
This also make it assume that a single number is meant to be the rating
(instead of the user). That should make editing the rating a bit more
straight forward (if one doesn't care about the user and play counter).
* Propose the usage of the popularity type in general for the rating field
so GUIs can show an appropriate UI element
* Do not just propose the popularity type for ID3v2 tags so a uniform UI
element can be shown accross tag formats; and API to convert from a
uniform scale is still TODO
That an automatic conversion happens for different types but not
for different encodings was always a bit odd.
This makes writing tests easier and comparing values within the
tag editor does not rely on choosing a particular encoding.