feat: Initial instagram integration implementation

[pyneda]

This PR implements an initial implementation of a similar functionality than the existing for Twitter, but for Instagram.

Few notes:

• Hashtags to follow can be defined from the admin interface
• It uses the instagrapi library to handle the communication with Instagram
• It allows to get data without authentication (even though Instagram may block us), authenticate with username and password provided via settings (this might fail in some cases due to Instagram requiring a 2FA challenge) or to create a session handling the challenge via a django management command create_instagram_session and saving the session data to the database for further use
• How many recent posts should be gathered per each hashtag can be configured via settings
• It still uses the existing Address/Location models used for Twitter, so we can keep using the same endpoints
• Also uses the ask_to_zekai functionality to get the Location/Address, even though from Instagram we can get the address and coordinates from the posts
• The LocationSerializer includes a new instagram_raw field. It could also be made to just use the raw field for both Twitter/Instagram getting the serializer dynamically

Update: I have noted that most of the people asking for help on Instagram does it on specific posts comments (such as: https://www.instagram.com/p/CoX7F0Lt0F2/), due to this I have also added the following functionality to the PR:

• Allow to define posts whose comments should be tracked
• Fetch and save the comments that contain certain words (same as used on the Twitter query) and analyze them with zekai to get the Address/Location
• Have also made some of the ask_to_zekai functionality a bit more reusable under applications/core/helpers.py. Not added it into the twitter side due to possible merge conflicts later.
• Have not added the comments to the APIs yet, as I'm not sure how this is wanted, but the serializer is ready and should be trivial to add.

[pyneda]

I have seen the whole app structure changed since I started implementing this feature. If you could confirm you are interested in using Instagram as a data source, I could update it to fit with the current implementation.

@hmert @ferhatbostanci @eserozvataf @ahmetkotan