Ability to report an issue

We don't have an official design from brio but this feature is already implemented in the app - we can use the app designs for that.

Design from Mobile App:
report proposal: https://zpl.io/aglReOA
hidden reported proposal view: https://zpl.io/Md7M08N
hide proposal - moderator view: https://zpl.io/40yKxqp
report discussion: https://zpl.io/RMBy830
hide discussion - moderator view: https://zpl.io/W4rAEK1
report comment: https://zpl.io/XYZQNYX
hide comment - moderator view: https://zpl.io/ll4z0rk

BE endpoint to report:
`POST /moderation/report`
Check out [validation schema](https://github.com/daostack/common-backend/blob/staging/functions/src/shared/schemas/reportContent.ts) for the endpoint.

BE endpoint to hide:
`POST /moderation/hide`
Check out [validation schema](https://github.com/daostack/common-backend/blob/staging/functions/src/shared/schemas/hideContent.ts) for the endpoint.

Only member with permission either `MemberPermission.Founder`, or `MemberPermission.Moderator` can hide something.
Hidden info should be displayed for proposals and discussions.
When a proposal is hidden, a `moderation` field is added to the proposal entity on BE.

From the conversation with Moore:
- only moderators can see hidden proposals/discussions/messages, regular user doesn't see them at all;
- everyone can see info about the last report;
- everyone can report smtg again;
- everyone can report, even if user is not logged in.


Start by reviewing the existing app implementation and the reportContent.ts and hideContent.ts validation schemas linked in the issue. Trace the moderation/report and moderation/hide flows for proposals, discussions, and comments, including founder or moderator permissions. Done means the reported and hidden states match the linked designs and the stated visibility rules.

Written by the indexing model from the issue text.