Breakpoint not finding source file when using a registered transpiler

[JustinGrote]

Describe the bug
Continuation of microsoft/vscode-test-cli#9 (comment)

To Reproduce
Steps to reproduce the behavior:

1. Make a debug config that uses esbuild/register to transpile the files with sourcemap enabled (you could use tsc-node or any other for this purpose)
2. Set a breakpoint and run extension host to that file
3. Breakpoint hits, opens editor to ephemeral transpiled TS file breakpoint. Sourcemap info is present

Expected: It would open to the original file location specified in the sourcemap, not the ephemeral version produced via the register transpiler.

Of note, the editor window shows the URL of the file "correctly", even though this isn't the actual content of the file.

Log File

vscode-debugadapter-7381afb9.json.gz
(nothing obvious in the DAP logs)

VS Code Version: 1.94.1

Additional context
Decoded base64 of the sourcemap:

{
  "version": 3,
  "sources": ["c:\\Users\\jgrote\\Projects\\vscode-adapter\\test\\extension.test.ts"],
  "sourcesContent": ["import { workspace } from \"vscode\"\n\ndescribe('test', () => {\n\tit('test', async () => {\n\t\tawait workspace.getConfiguration('editor').update('tabSize', 8, true)\n\t\tconst actual = workspace.getConfiguration('editor').get('tabsize')\n\t\tactual?.should.equal(8)\n\t})\n})\n"],
  "mappings": ";;AAAA,oBAA0B;AAE1B,SAAS,QAAQ,MAAM;AACtB,KAAG,QAAQ,YAAY;AACtB,UAAM,wBAAU,iBAAiB,QAAQ,EAAE,OAAO,WAAW,GAAG,IAAI;AACpE,UAAM,SAAS,wBAAU,iBAAiB,QAAQ,EAAE,IAAI,SAAS;AACjE,YAAQ,OAAO,MAAM,CAAC;AAAA,EACvB,CAAC;AACF,CAAC;",
  "names": []
}