[mlir] Fix worklist bug in MultiOpPatternRewriteDriver

When `strict = true`, only pre-existing and newly-created ops are rewritten and/or folded. Such ops are stored in `strictModeFilteredOps`.

Newly-created ops were previously added to `strictModeFilteredOps` after calling `addToWorklist` (via `GreedyPatternRewriteDriver::notifyOperationInserted`). Therefore, newly-created ops were never added to the worklist.

Also fix a test case that should have gone into an infinite loop (`test.replace_with_new_op` was replaced with itself, which should have caused the op to be rewritten over and over), but did not due to this bug.

Differential Revision: https://reviews.llvm.org/D141141