Backport into main the max number of files limit that is checked by elasticity during merge operations

[cshannon]

As part of #3934, merge in elasticity was updated with a new property called TABLE_MERGE_FILE_MAX which is used to limit the maximum number of files that a merge operation will process. This was done to prevent a massive number of files in a single tablet because we need a single tablets metadata to fit into memory at once or else problems will occur with scans and other operations. We should look at backporting this property and applying the same checks to no-chop merge in 3.1.