Feature: Add "Authentication Method" to allow existing users to sign in with LDAP (#2143)

* adds authentication method for users

* fix db migration with postgres

* tests for auth method

* update migration ids

* hide auth method on user creation form

* (docs): Added documentation for the new authentication method

* update migration

* add  to auto-form instead of having hidden fields

alembic/versions/2023-02-22-21.45.52_38514b39a824_add_auth_method_to_user_table.py

@@ -0,0 +1,43 @@
+"""add auth_method to user table
+
+Revision ID: 38514b39a824
+Revises: b04a08da2108
+Create Date: 2023-02-22 21:45:52.900964
+
+"""
+import sqlalchemy as sa
+
+import mealie.db.migration_types
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "38514b39a824"
+down_revision = "b04a08da2108"
+branch_labels = None
+depends_on = None
+
+
+def is_postgres():
+    return op.get_context().dialect.name == "postgresql"
+
+
+authMethod = sa.Enum("MEALIE", "LDAP", name="authmethod")
+
+
+def upgrade():
+    if is_postgres():
+        authMethod.create(op.get_bind())
+
+    op.add_column(
+        "users",
+        sa.Column("auth_method", authMethod, nullable=False, server_default="MEALIE"),
+    )
+    op.execute("UPDATE users SET auth_method = 'LDAP' WHERE password = 'LDAP'")
+
+
+def downgrade():
+    with op.batch_alter_table("users", schema=None) as batch_op:
+        batch_op.drop_column("auth_method")
+
+    if is_postgres():
+        authMethod.drop(op.get_bind())