--solution command line option not honoured when multiple solutions available in project

[lem102]

Hi,

First of all, thanks for csharp-ls 🙏.

When I start csharp-ls in a directory that contains multiple solutions like this:

$ ls
solution1.sln solution2.sln xyz.csproj Program.cs ...
$ csharp-ls --solution solution2.sln

I can see from the output in emacs that despite providing a solution to load, the code will still attempt to load all the projects in the directory one at a time. This works, but if you have a directory that contains 100+ projects, the startup time can get a little long 😅.

[eglot] Connected! Server `EGLOT (csharpLsTestSolution/(csharp-ts-mode csharp-mode))' now managing `(csharp-ts-mode csharp-mode)' buffers in project `csharpLsTestSolution'.
[eglot] Server reports (type=4): csharp-ls: attempting to find and load solution based on root path ("/home/jacobl/dev/csharpLsTestSolution")..
[eglot] Server reports (type=4): csharp-ls: 2 solution(s) found: [/home/jacobl/dev/csharpLsTestSolution/csharpLsTestSolution2.sln, /home/jacobl/dev/csharpLsTestSolution/csharpLsTestSolution.sln]
[eglot] Server reports (type=4): csharp-ls: no or multiple .sln files found on /home/jacobl/dev/csharpLsTestSolution
[eglot] Server reports (type=4): csharp-ls: looking for .csproj/fsproj files on /home/jacobl/dev/csharpLsTestSolution..
[eglot] Server reports (type=4): csharp-ls: OK, 1 project files loaded

This seems like it should be a simple problem to fix (if it is indeed a problem), but I've never coded F# before 😢 so it'll take me a while before I can submit a PR.