"Go to Definition" fails for some scenarios

<!-- Please provide a detailed description of the bug. --> <!-- Note: This template is not meant for security vulnerabilities disclosure --> <!-- Any such issue, created in this repo, will be deleted on sight --> <!-- Instead please report vulnerabilities to the Eclipse Foundation's security team --> <!-- For more details, please read SECURITY.md in the repository root --> ### Bug Description: "Go to Definition"(Ctrl + Click) fails in some scenarios which VS Code could be successful <!-- Please provide clear steps to reproduce the bug. --> ### Steps to Reproduce: Scenario 1: I defined **Function_A(int argument1, in argument2)** in a header file then I use it as **Function_A(int argument1)** in my cpp file now Ctrl + Click on **Function_A(int argument1)**, it fails to go to the header file Scenario 2: I defined a struct in header file **typedef struct _MOCK_UP { int field1; int field2; } MOCK_UP; MOCK_UP mockup;** then I use it like **mockup.field2 = ;** in my cpp file now Ctrl + Click on **mockup.field2 = ;**, it fails to go to the header file if we do the same action in VS Code, it can "Go to Definition" successfully <!-- Please provide any additional information available. --> <!-- Additional information can be in the form of logs, screenshots, screencasts. --> ### Additional Information - Operating System: All - Theia Version: All <!-- 💙 Eclipse Theia is community-supported. If you find it valuable, consider sponsoring the project: https://theia-ide.org/support/ -->