[pruner] amend base pruner API to match base sparsifier (#63178)

[pruner] amend base pruner API to match base sparsifier (#63178)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63178

Update base pruner API to match base sparsifier API as defined in D28970960 / PR58955

Changes include:
- `enable_mask_update = True` in `__init__`
- `prepare` takes model and config instead of constructor
- convert functionality renamed to `squash_mask`, `convert` method call now raises Error
- `activation_handles` ad `bias_handles` initialized in `_prepare` instead of constructor
ghstack-source-id: 136467595

Test Plan:
Function names updates according to changes

`buck test mode/dev-nosan //caffe2/test:ao -- TestBasePruner`

https://pxl.cl/1MTgH

TODO will need to modify `fbcode/scripts/kazhou/fusion_tests.py` to use new API

Reviewed By: z-a-f

Differential Revision: D30287179

fbshipit-source-id: d4727bea1873b500f2d4bb784db26d532bf26cce