feat: slack integration (#874)

* feat: init slack integration

* dev: create model and update existing view for slack

* dev: update slack sync model and create view to install slack

* dev: workspace integration query

* dev: update the metadata validation for access_token and team_id and save config to database

* dev: update validation for team_id

* dev: update validation

* dev: update validations

* dev: remove bot access token field from sync

* dev: handle integrity exception

apiserver/plane/db/models/integration/__init__.py

@@ -1,2 +1,3 @@
 from .base import Integration, WorkspaceIntegration
 from .github import GithubRepository, GithubRepositorySync, GithubIssueSync, GithubCommentSync
+from .slack import SlackProjectSync

apiserver/plane/db/models/integration/slack.py

@@ -0,0 +1,32 @@
+# Python imports
+import uuid
+
+# Django imports
+from django.db import models
+
+# Module imports
+from plane.db.models import ProjectBaseModel
+
+
+class SlackProjectSync(ProjectBaseModel):
+    access_token = models.CharField(max_length=300)
+    scopes = models.TextField()
+    bot_user_id = models.CharField(max_length=50)
+    webhook_url = models.URLField(max_length=1000)
+    data = models.JSONField(default=dict)
+    team_id = models.CharField(max_length=30)
+    team_name = models.CharField(max_length=300)
+    workspace_integration = models.ForeignKey(
+        "db.WorkspaceIntegration", related_name="slack_syncs", on_delete=models.CASCADE
+    )
+
+    def __str__(self):
+        """Return the repo name"""
+        return f"{self.project.name}"
+
+    class Meta:
+        unique_together = ["team_id", "project"]
+        verbose_name = "Slack Project Sync"
+        verbose_name_plural = "Slack Project Syncs"
+        db_table = "slack_project_syncs"
+        ordering = ("-created_at",)