Fix bad interior cell data in db

I had a bad unique index on the `cells` table. This commit does not fix
it but has two backfill scripts that will allow me to fixup the data
before creating the new unique index.

`is_base_game` identifies cells that are from the `Skyrim.esm` shipped
with the game (and not from some mod that happens to also have a
`Skyrim.esm` with a 0,0 cell with a different form id, see:
https://github.com/thallada/modmapper-web/issues/8).

`dump_cell_data` now only dumps cells from `is_base_game` cells.

`deduplicate_interior_cells` removes duplicate cell and plugin_cell rows
caused by the buggy index.

I will need to upgrade the database and create a new index in a later
commit.

src/plugin_processor.rs

@@ -15,7 +15,7 @@ use crate::models::{plugin_cell, plugin_cell::UnsavedPluginCell};
 use crate::models::{plugin_world, plugin_world::UnsavedPluginWorld};
 use crate::models::{world, world::UnsavedWorld};
 
-fn get_local_form_id_and_master<'a>(
+pub fn get_local_form_id_and_master<'a>(
     form_id: u32,
     masters: &'a [&str],
     file_name: &'a str,
@@ -124,6 +124,7 @@ pub async fn process_plugin(
                         y: cell.y,
                         world_id,
                         is_persistent: cell.is_persistent,
+                        is_base_game: false,
                     }
                 })
                 .collect();