Fix/change email wizard

Commit 1: - Leave log notes when changing email

• Inform of the change in both partner and contract pages involved.

Notes visible in the contract whose email has been changed:

And also from the partner, where the wizard has been called:

Commit 2: - Apply email changes to OC

• Add contactInformation to crm_account_hierarchy to mantain the OC Customer contact information independently from the each billing account's information. (same example as next joint image)

• Pick email from contract instead from the one from its invoicing partner to apply it to the OC billing information ('contract information')

• If we have multiple contract.email_ids, pick the first one and send the others as CC emails in the 'electronic billing' zone (see picture)

Result of one contract with 3 emails in OC:

Commit 3: - Update tests