Adding option to explicitly specify build directory

### Description
`mbed-tools configure` stores target specifc configuration (.mbedbuild/) in a project dir - this can't be overridden with different path.
It is a little bit inconvenient, especially in situation when we want to use single project directory to work with multiple HW targets (or with tests on multiple HW in CI/CD).

Maybe we could add a new option to `mbed-tool configure | mbed-tool compile` commands, which would explicitly specify build directory where .mbedbuild will be created (something similar to `-B` flag from cmake >3.19)

For example:
```
mbed-tools configure -B ...
cmake -B ...
cmake --build
```
or
```
mbed-tools compile -B ...
```