Multiple Managers: Review code that modifies metadata table, modify it to use Ample

[dlmarion]

There are classes that update the metadata table (e.g. MetadataTableUtil) that do not use Ample. Suggest finding and modifying these classes to use Ample in preparation for having multiple Manager processes and Ample using conditional mutations.

[ddanielr]

I started looking into this.

[ddanielr]

So this has turned into a bit of a rats nest.

I started working on removing the managerMetadataUtil class and separating those functions into their respective calling classes.

While there were some improvements there, overall it uncovered a LOT of various actions happening in managerMetadataUtil and MetadataTableUtil that are not using ample for metadata actions.

The majority of these all fall under Split Tablet and Clone Table operations.

I also found that ProblemReport uses a reserved prefix of "~err_" but is not included in the metadata schema at all.

[ctubbsii]

@ddanielr The metadata has a few distinct sections. The tablets section is first, and covers all the metadata for tablets. After that, there is a separate entire section starting with ~ that is for metadata that is not part of a particular tablet. That's where the ~del entries exist for the accumulo-gc to pick up files that are candidates for deletion, and I guess the ~err section also exists in there. Those regions of the metadata table are independent of the schema for tablet metadata.