Add a new command to help users migrate launch.json configurations

[st0012]

Motivation

Ruby LSP now provides better logging and error messages when the debugger failed to start. And we plan to keep improving the debugging experience in the future.

If users are currently using vscode-rdbg and want to try Ruby LSP, we can help them migrate their launch.json configurations to the format used by Ruby LSP.

Implementation

1. Add a migrateLaunchConfiguration command
2. In the command, fetch users' launch configurations and apply the changes needed for the migration

The 2nd commit is to fix the message formatting issue caused by #2957

Example Result

This is from a real-world Rails project:

diff --git a/.vscode/launch.json b/.vscode/launch.json
index cc686cd1069..bd05d0d7c60 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,58 +6,47 @@
   "configurations": [
     {
       "name": "Attach",
-      "type": "rdbg",
+      "type": "ruby_lsp",
       "request": "attach"
     },
     {
       "name": "Rails Server",
-      "type": "rdbg",
-      "cwd": "${workspaceRoot}",
-      "useBundler": true,
+      "type": "ruby_lsp",
       "request": "launch",
       "env": {
         "DISABLE_SPRING": "1"
       },
-      "command": "${workspaceRoot}/bin/rails",
-      "script": "server",
-      "args": [],
-      "askParameters": false
+      "program": "bin/rails server"
     },
     {
       "name": "Minitest - current line",
-      "type": "rdbg",
-      "cwd": "${workspaceRoot}",
-      "useBundler": true,
+      "type": "ruby_lsp",
       "request": "launch",
       "env": {
         "DISABLE_SPRING": "1"
       },
-      "command": "${workspaceRoot}/bin/rails",
-      "script": "test",
-      "args": ["${file}:${lineNumber}"],
-      "askParameters": false
+      "program": "bin/rails test ${file}:${lineNumber}"
     },
     {
       "name": "Minitest - current file",
-      "type": "rdbg",
-      "cwd": "${workspaceRoot}",
-      "useBundler": true,
+      "type": "ruby_lsp",
       "request": "launch",
       "env": {
         "DISABLE_SPRING": "1"
       },
-      "command": "${workspaceRoot}/bin/rails",
-      "script": "test",
-      "args": ["${file}"],
-      "askParameters": false
+      "program": "bin/rails test ${file}"
     },

And every action works after the migration.

Automated Tests

No test

Manual Tests

1. Find an application that uses rdbg in its launch.json
2. Run the new Migrate launch.json configurations from rdbg to ruby_lsp command through VS Code's command palette
3. Verify that the updated entries still function the same

[andyw8]

Suggested change

	"title": "Migrate launch.json configurations from rdbg to ruby_lsp",
	"title": "Migrate debug launch.json configurations from rdbg to ruby_lsp",

[st0012]

I don't think it's necessary to add debug before it as there's no other types of launch.json.