Definitions in mbed_lib.json are not generated for target link libraries

**Describe the bug**
When adding a target library via target_link_library, the tool does not generate the necessary definitions from the libraries 'mbed_lib.json`. This issues was encountered on the blinky bare-metal example

**To Reproduce**
Steps to reproduce the behavior:
1. Add library (i.e. mbed-events) as a target link library
2. Configure or compile application: `mbedtools configure -t ARM -m RZ_A1H`
3. Definitions for library can't be found `mbed_config.cmake`

**Expected behavior**
Tool should automatically generate macros from that linked libraries mbed_lib.json configs .i.e. MBED_CONF_EVENTS_SHARED_EVENTSIZE=2048 for the following:
``` json
"shared-stacksize": {
"help": "Stack size (bytes) for shared event queue thread",
"value": 2048
}
```
**Screenshots**
If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**
- OS: [MacOS]
- Version: [11.2.1]

**Mbed (please complete the following information):**
- Device: [RZ_A1H]
- Mbed OS Version: [6.9.0]
- Mbed CLI 2 Version: [7.5.0]

**Additional context**
Add any other context about the problem here.

Reproduce the issue with mbedtools configure -t ARM -m RZ_A1H after linking mbed-events, then inspect mbed_config.cmake and the linked library's mbed_lib.json. Done means the library definitions, including MBED_CONF_EVENTS_SHARED_EVENTSIZE=2048, are generated and available to the application.

Written by the indexing model from the issue text.