Change annotations to use a NamedTuple (JuliaLang#55741)

Due to popular demand, the type of annotations is to be changed from a
`Tuple{UnitRange{Int}, Pair{Symbol, Any}}` to a `NamedTuple{(:region,
:label, :value), Tuple{UnitRange{Int}, Symbol,
Any}}`.

This requires the expected code churn to `strings/annotated.jl`, and
some changes to the StyledStrings and JuliaSyntaxHighlighting libraries.

Closes JuliaLang#55249 and closes JuliaLang#55245.

Author: tecosaur

base/strings/annotated.jl

@@ -816,12 +816,12 @@ function AnnotatedString(chars::AbstractVector{C}) where {C<:AbstractChar}
             end
         end
     end
-    annots = Tuple{UnitRange{Int}, Pair{Symbol, Any}}[]
+    annots = RegionAnnotation[]
     point = 1
     for c in chars
         if c isa AnnotatedChar
             for annot in c.annotations
-                push!(annots, (point:point, annot))
+                push!(annots, (point:point, annot...))
             end
         end
         point += ncodeunits(c)

base/strings/io.jl

@@ -0,0 +1 @@
+401bb32ca43a8460d6790ee80e695bb5

deps/checksums/JuliaSyntaxHighlighting-19bd57b89c648592155156049addf67e0638eab1.tar.gz/md5

@@ -0,0 +1 @@
+db2c732d3343f5a8770b3516cdd900587d497feab2259a937d354fac436ab3cb099b0401fb4e05817e75744fb9877ab69b1e4879d8a710b33b69c95b7e58d961

deps/checksums/JuliaSyntaxHighlighting-19bd57b89c648592155156049addf67e0638eab1.tar.gz/sha512

@@ -0,0 +1 @@
+f053c84279a8920f355f202e605842af

deps/checksums/JuliaSyntaxHighlighting-b89dd99db56700c47434df6106b6c6afd1c9ed01.tar.gz/md5

@@ -0,0 +1 @@
+b6f4c1d6c0dc73a520472746c96adff506e5405154e4b93d419e07b577b01804d2fc87d4a6cac48a136777579bebf8388c2c1e54f849b51e233138d482146b4f