Refactoring census generation on Votecaster and internalize it with Census3.

[ferranrego]

Due to stability issues with Airstack and the deprecation of several of their services, we need to revise our census generation approach. The plan is to internalize census creation using our Census3 service.

Product requirements:

1-Click Poll Creation:

1. Remove the option to create token-based polls
2. Add an option called Token-based polls. If you select it, then it gives you a message that this option is only available for communities and gives you a CtA button to create your community.
3. POAP-based censuses: Utilize Census3 or the POAP API directly. To discuss → how to do the POAP discoverability.

Community Creation:

1. Census: Always use Census3 (except for ERC1155 Tokens?)
2. Creation of the census for the first time: Inform users that the process can take a long time as it's the first time, and that only after the scan is complete the user can start creating polls (e.g., scanning a token for the first time). Implement a progress bar to indicate this. The scanning process should run in the background and, if possible, occur after the user has completed the community creation process.
3. Token addition in the UI: Allow users to add their tokens using the format [chain] [SC address] that we are already using.

[ferranrego]

@lucasmenendez comments that is better to use the POAP API directly for POAP-based censuses