[microTVM] Remove codegen parameters from Target

[areusch]

We have been taking on technical debt by injecting codegen- and whole-compiler parameters into the Target string. This causes the undesirable side effect that when these parameters are changed, tuning logs are considered invalid, even though these parameters currently have no effect on AutoTVM results. #9352 started down this path, but we need to clean up the API before we can make a release, and address the effect on tuning logs to ensure there were no unintended side-effects. Example parameters are:

• -runtime=c
• -unpacked-api=1
• -executor=aot
• -interface-api=c
• -link-params=1

cc @Mousius @alanmacd @gromero @mehrdadh