- Ambiguous `raw_value()` method is replaced with `line_number()` and
`span()`.
- `line_name()` that before returned either line name or area name is
replaced with `line_name()` and `area_name()`.
- `Position` type is replaced with `Line` and `Area` type so we don't
have to guess while doing layout.
Affected test expectations:
- `template-lines-and-areas` - improvement over what we had before.
- `named-tracks` - rebaseline a giant test. will have to split it into
smaller tests in the future.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Implement span correctly when indicated in the grid-column-start,
grid-row-start, etc. CSS properties. Previously it had been implemented
as if span was something that went alongside the position property, but
actually it seems like if you do 'span 3' in the grid-column-start
property, for example, this means it literally spans 3 blocks, and the
3 has nothing to do with position.