[Issue #3446] Create database table for saved searches (#3461)

## Summary
Fixes #3446

### Time to review: 10 mins

## Changes proposed
Add user saved search model
Add DB migration

## Context for reviewers
This lays the groundwork for an API to save user searched.

## Additional information
Generated table:
<img width="1035" alt="Screenshot 2025-01-08 at 11 21 58 AM"
src="https://github.com/user-attachments/assets/7d8c9f6c-2d72-4d2e-909e-f40178886837"
/>

api/src/db/migrations/versions/2025_01_08_create_saved_searches_table.py

@@ -0,0 +1,62 @@
+"""Create saved searches table
+
+Revision ID: cc2912373d5b
+Revises: 232a9223ed9b
+Create Date: 2025-01-08 16:20:40.898481
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = "cc2912373d5b"
+down_revision = "232a9223ed9b"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        "user_saved_search",
+        sa.Column("saved_search_id", sa.UUID(), nullable=False),
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("search_query", postgresql.JSONB(astext_type=sa.Text()), nullable=False),
+        sa.Column("name", sa.Text(), nullable=False),
+        sa.Column(
+            "created_at",
+            sa.TIMESTAMP(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.Column(
+            "updated_at",
+            sa.TIMESTAMP(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.ForeignKeyConstraint(
+            ["user_id"], ["api.user.user_id"], name=op.f("user_saved_search_user_id_user_fkey")
+        ),
+        sa.PrimaryKeyConstraint("saved_search_id", name=op.f("user_saved_search_pkey")),
+        schema="api",
+    )
+    op.create_index(
+        op.f("user_saved_search_user_id_idx"),
+        "user_saved_search",
+        ["user_id"],
+        unique=False,
+        schema="api",
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(
+        op.f("user_saved_search_user_id_idx"), table_name="user_saved_search", schema="api"
+    )
+    op.drop_table("user_saved_search", schema="api")
+    # ### end Alembic commands ###

api/src/db/models/user_models.py

@@ -2,7 +2,7 @@
 from datetime import datetime
 
 from sqlalchemy import BigInteger, ForeignKey
-from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.dialects.postgresql import JSONB, UUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from src.adapters.db.type_decorators.postgres_type_decorators import LookupColumn
@@ -24,6 +24,10 @@ class User(ApiSchemaTable, TimestampMixin):
         cascade="all, delete-orphan",
     )
 
+    saved_searches: Mapped[list["UserSavedSearch"]] = relationship(
+        "UserSavedSearch", back_populates="user", uselist=True, cascade="all, delete-orphan"
+    )
+
 
 class LinkExternalUser(ApiSchemaTable, TimestampMixin):
     __tablename__ = "link_external_user"
@@ -82,3 +86,18 @@ class UserSavedOpportunity(ApiSchemaTable, TimestampMixin):
     opportunity: Mapped[Opportunity] = relationship(
         "Opportunity", back_populates="saved_opportunities_by_users"
     )
+
+
+class UserSavedSearch(ApiSchemaTable, TimestampMixin):
+    """Table for storing saved search queries for users"""
+
+    __tablename__ = "user_saved_search"
+
+    saved_search_id: Mapped[uuid.UUID] = mapped_column(UUID, primary_key=True, default=uuid.uuid4)
+
+    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey(User.user_id), index=True)
+    user: Mapped[User] = relationship(User, back_populates="saved_searches")
+
+    search_query: Mapped[dict] = mapped_column(JSONB)
+
+    name: Mapped[str]