Remove packages migrated to mil_common

[DSsoto]

We should start removing duplicate packages in the repo.

This is some of what needs to go:

• sub8_perception/*/sub8_vision_lib
• sub8_sonar
• hydrophones
• paulboard
• some of sub8_tools
• some of sub8_msgs

Be sure to reference your PR if you do any of this and/or add to this list.

[sentree]

Is taking care of this on NaviGator right now out of the question? I feel like if we don't it will be a mess to do next year.

[sentree]

Also, I would advise that we merge mil_common #15 before this.

[DSsoto]

Only if it's a low effort thing, we don't want to sink a lot of time into making NaviGator compatible right now.

Have you even reviewed any of it or commented that it looks good? No one has.

[kev-the-dev]

I'm going to make this my pet project for the week. Plan is as follows:

1. Remove packages/files duplicated in mil_common
2. Use git grep with awk to replace strings like 'sub8_ros_tools' with 'mil_ros_tools'
3. Look at diff to verify nothing crazy happened
4. Start testing things to see what's broken

I'll open a PR once I get to step 4 to see if anyone notices anything wacky.

[sentree]

Can this be closed now that #216 has been merged?