db,view: drop the artificial limit on view update mutation size
db,view: drop the artificial limit on view update mutation size

The series which split the view update process into smaller parts
accidentally put an artificial 10MB limit on the generated mutation
size, which is wrong - this limit is configurable for users,
and, what's more important, this data was already validated when
it was inserted into the base table. Thus, the limit is lifted.

Tests: unit(release), dtest(wide_rows_test)

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla