Sharing tables readonly with other users

- Added sharing feature for table owners to share their tables with
  other registered users.
- Fixed a bug where the wrong entries would be deleted or modified when
  searching or filtering.

inventur_db/migrations/2024-08-31-094645_create_shares/down.sql

@@ -0,0 +1 @@
+DROP TABLE shares;

inventur_db/migrations/2024-08-31-094645_create_shares/up.sql

@@ -0,0 +1,13 @@
+CREATE TABLE shares (
+       id INTEGER AUTO_INCREMENT UNIQUE NOT NULL,
+       PRIMARY KEY(id),
+       sharee_id INTEGER NOT NULL,
+       FOREIGN KEY (sharee_id) REFERENCES users(id)
+       ON DELETE CASCADE
+       ON UPDATE CASCADE,
+       tblid INTEGER NOT NULL,
+       FOREIGN KEY (tblid) REFERENCES jrtables(id)
+       ON DELETE CASCADE
+       ON UPDATE CASCADE,
+       readonly BOOLEAN NOT NULL DEFAULT true
+);