Excise JuliaHighighting, StyledStrings from stdlib and AnnotatedX from Base

[KristofferC]

This is a test branch for me to be able to easier see the effects StyledStrings has on e.g. latency and to provide a reference for #57998

As an example, running

begin
    using Pkg
    ENV["JULIA_PKG_PRECOMPILE_AUTO"] = 0
    Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
    @time @eval Pkg.add("Example")
 end

on this branch

is

0.538453 seconds (2.96 M allocations: 177.956 MiB, 6.23% gc time, 87.22% compilation time: 45% of which was recompilation)

while on master it is

1.337046 seconds (6.75 M allocations: 371.075 MiB, 8.00% gc time, 91.44% compilation time: 71% of which was recompilation)

Also, even on this branch, loading REPL causes extra latency:

./julia -e '
begin
using Pkg
ENV["JULIA_PKG_PRECOMPILE_AUTO"] = 0
Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
@time @eval Pkg.add("Example")
end
'
   Resolving package versions...
No packages added to or removed from `~/.julia/environments/v1.13/Project.toml`
No packages added to or removed from `~/.julia/environments/v1.13/Manifest.toml`
  0.249249 seconds (1.07 M allocations: 77.725 MiB, 9.64% gc time, 73.53% compilation time: <1% of which was recompilation)

which I think is due to #58000.

---

What is lost on this branch is:

• Markdown julia code + REPL Expr highlighting
• Clickable paths in Profile

It should be fairly easy to add those back with a tweak to printstyled for the link and some regex stuff for the highlighting.

I think the Profile tests will fail here because the PR that added StyledStrings dependency also did some other stuff and I don't think I detangled it correctly.