New integrations: Bitsight and Mimecast

New integrations **Bitsight SPM** and **Mimecast Email Security** have entered **BETA** phase. ## Bitsight SPM [BETA] - Collect `findings` with vulnerability and asset details into Sekoia ([documentation](https://docs.sekoia.io/xdr/features/collect/integrations/cloud_and_saas/bitsight_spm/)). ## Mimecast Email Security [BETA] - Collect `email gateway logs` into Sekoia ([documentation](https://docs.sekoia.io/xdr/features/collect/integrations/email/mimecast_email_security/)).