Max length for db fields too small - 2048

[matteo-s]

Various fields which are supposed to contain JWTs are set to a maxLength of 2048 which is too small for any real usage.
For example in fetched entity

spid-cie-oidc-django/spid_cie_oidc/entity/migrations/0008_fetchedentitystatement_jwt.py

Line 16 in 2b0c2ef

field=models.CharField(default="", max_length=2048),

The smallest valid JWT we can build which contains federation metadata + rp metadata is 2083, but also the examples you distribute with this project are "over quota", like the one for relying-party.org:8001 which is 4218 characters.

If you copy/paste the jwt in the form at http://trust-anchor.org:8000/admin/spid_cie_oidc_entity/fetchedentitystatement/add/ the backend app will break, because the input field will just truncate the JWT at 2048 and thus produce garbage which the backend tries to read as JWT, failing.

[peppelinux]

it should be changed to models.TextField

good catch @matteo-s

[rglauco]

fixed in #291