Location metadata on DAP output events are not absolute paths #4573
Description
The links on the right side of the debug console here are not clickable, they are relative paths which resolve to "C:\Users\danny\AppData\Local\Programs\Microsoft VS Code\test\lsp\temporary_overlay_operation_test.dart".
[11:40:43 AM] [DAP] [Info] <== {"seq":27,"type":"event","body":{"category":"stderr","column":5,"line":23,"output":"test\\lsp\\temporary_overlay_operation_test.dart 23:5 TemporaryOverlayOperationTest.expectContent\n","source":{"name":"C:\\Users\\danny\\AppData\\Local\\Programs\\Microsoft VS Code\\test\\lsp\\temporary_overlay_operation_test.dart","path":"C:\\Users\\danny\\AppData\\Local\\Programs\\Microsoft VS Code\\test\\lsp\\temporary_overlay_operation_test.dart"}},"event":"output"}
[11:40:43 AM] [DAP] [Info] <== {"seq":28,"type":"event","body":{"category":"stderr","column":7,"line":83,"output":"test\\lsp\\temporary_overlay_operation_test.dart 83:7 TemporaryOverlayOperationTest.test_pausesWatcherEvents.<fn>\n","source":{"name":"C:\\Users\\danny\\AppData\\Local\\Programs\\Microsoft VS Code\\test\\lsp\\temporary_overlay_operation_test.dart","path":"C:\\Users\\danny\\AppData\\Local\\Programs\\Microsoft VS Code\\test\\lsp\\temporary_overlay_operation_test.dart"}},"event":"output"}