Change REPL completion for U+022D8 character

[saf-dmitry]

AMS defines \lll command for U+022D8 (Very Much Less-Than) character, which is more "standard" than currently defined \verymuchless and more consistent with using \ggg for U+022D9 (Very Much Greater-Than) character.

This should resolve #59387.

[PallHaraldsson]

I believe you can have both, i.e. still the Unicode name: https://www.compart.com/en/unicode/U+22D8

And likely should, then also for the greater type.

[inkydragon]

Test failed seems related:

REPL                                      (17) |         failed at 2025-11-20T21:50:42.901
2025-11-21 05:50:42 null
Test Failed at /cache/build/tester-amdci5-13/julialang/julia-master/julia-b0f70e2117/share/julia/stdlib/v1.13/REPL/test/docview.jl:22
2025-11-21 05:50:43 null
  Expression: all(duplicates .∈ Ref(keys(REPLCompletions.symbols_latex_canonical)))
2025-11-21 05:50:43 null
   Evaluated: all(Bool[1, 1, 1, 1, 1, 1, 1, 1, 1, 1  …  1, 1, 0, 1, 1, 1, 1, 1, 1, 1])

https://buildkite.com/julialang/julia-master/builds/52218/steps/canvas?sid=019aa310-1663-4302-8e3a-21a0e9443678#019aa310-1691-4bea-bfe9-2f0e2688e1b6/1181-1590