Add lint for `for i=1:length(v)`

[non-Jedi]

After reading https://yuri.is/not-julia/, one takeaway is that this pattern is a frequent source of bugs when combined with OffsetArrays (especially with the use of @inbounds). In almost all cases, 1:length(v) should be replaced with eachindex(v). If there's worry that this lint would be too intrusive for cases where you really want to iterate over the length of an array rather than its indices, this lint could be conditional on @inbounds being present.

[non-Jedi]

For bonus points, this lint could look within loops using like for i in eachindex(v) so that anywhere arithmetic is done on i is marked. Doing i+1 for the next element of an array is fine for OffsetArrays but will not work for e.g. StarWarsArrays.

[pfitzseb]

With #338 and julia-vscode/LanguageServer.jl#1086: