Multiple certificate_status filter

[annybs]

At the moment, listCertificates() only supports filtering by a single certificate_status:

zerossl/lib/types.ts

Line 77 in 6f32466

certificate_status?: 'draft' | 'pending_validation' | 'issued' | 'cancelled' | 'expiring_soon' | 'expire'

ZeroSSL documentation indicates this can be provided as a comma-separated list to support multiple values. This could be accomplished by accepting an array filter and joining it in the query string.