feat:implement beneficiary fip0029

[hunjixin]

This is an implementation for FIP-0029 PR filecoin-project/specs-actors#1571 to provide Beneficiary address support. In this implementation, version and upgrading is not considered, that is, directly put the code change into the current version. The back-compliance could be done once the next version content is determined.

Closes #422

[anorth]

Thanks, this looks great so far. Could you please port the tests too?

[hunjixin]

@anorth could give a test example, i dont know how to write test in this project

[anorth]

See https://github.com/filecoin-project/builtin-actors/blob/master/actors/miner/tests/change_owner_address_test.rs and other files in that dir

[hunjixin]

why this pr's ci not running?

[anorth]

why this pr's ci not running?

It's possibly related to it being from a fork. @ZenGround0 @aarshkshah1992 do we have experience with this from other contributions?

[ZenGround0]

Thanks to @anorth and @galargh #510 is now merged and CI should run on next push. Give it a try and let me know if there's still a problem.

If push doesn't work try taking it out of draft and pushing too, and update us here about what (doesn't) work.

[hunjixin]

Thanks to @anorth and @galargh #510 is now merged and CI should run on next push. Give it a try and let me know if there's still a problem.

If push doesn't work try taking it out of draft and pushing too, and update us here about what (doesn't) work.

works fine

[anorth]

Thanks, I will review again now the tests are there

[anorth]

Thanks for the tests, great work.

Some minor comments, and a request for one new test to demonstrate what happens when the owner and beneficiary attempt to reduce the quota.

[ZenGround0]

Unfortunately I haven't given a thorough review yet and I'll be offline for a week but the high level looks good and the testing looks great. If necessary I will do a review after the fact so don't block on me if you need to merge before then.