* move jmap.request() to jmap.Client.request() and pass the Session
and a Logger to introduce checking the number of methodCalls within a
request not exceeding the limit of the Session, as well as error
handling and logging there instead of in each caller
* a few bugfixes:
- add a few missing Send() calls in logs
- correct the response tag matching for
GetMailboxChangesForMultipleAccounts
- fix typo in Identity.ReplyTo json serialization rune
- fix response tag in pkg/jmap/testdata/mailboxes1.json after
changing them to be prefixed by the accountId
* refactored the models to be strongly typed with structs and mapstruct
to decompose the dynamic parts of the JMAP payloads
* externalized large JSON strings for tests into .json files under
testdata/
* added a couple of fantasy Graph groupware APIs to explore further
options
* added k6 scripts to test those graph/me/messages APIs, with a setup
program to set up users in LDAP, fill their IMAP inbox, activate them
in Stalwart, cleaning things up, etc...
