feat(nvim): v0.11: Use native LSP, Completion, Diagnostics

- Move all language LSP configurations to `nvim/lsp`
- Move nvim LSP configurations to `nvim/lua/core`
- Remove LSP attach keymaps where default ones exists and are usable
- Reorged LSP attach keymaps per plugin
- Move Lazy.nvim configurations to `nvim/lua/core`
- `nvim/init.lua` cleaned to only load other files
- Uniform diagnostics symbols across lualine & gutter

common/.config/nvim/lsp/omnisharp.lua

@@ -0,0 +1,32 @@
+return {
+    cmd = { "omnisharp" },
+    handlers = {
+        ["textDocument/definition"] = function(...)
+            return require("omnisharp_extended").handler(...)
+        end,
+    },
+    enable_roslyn_analyzers = true,
+    organize_imports_on_format = true,
+    enable_import_completion = true,
+    enable_editorconfig_support = true,
+    enable_ms_build_load_projects_on_demand = false,
+    analyze_open_documents_only = false,
+    settings = {
+        dotnet = {
+            server = {
+                useOmnisharpServer = true,
+                useModernNet = true,
+            },
+        },
+        csharp = {
+            inlayHints = {
+                parameters = {
+                    enabled = true,
+                },
+                types = {
+                    enabled = true,
+                },
+            },
+        },
+    },
+}