Support new Azure CPU series

[r4victor]

Currently, dstack supports old generations of CPU series on Azure: Dsv3 and Esv4, which are either retired or soon to be retired. Support new generations: Dsv6 and Esv6. Also consider supporting entry level series (Av2) and burstable series (Bsv2).

Supporting Dsv3 and Esv4 requires building a NVMe image and marking its image definition as NVMe-supporting (https://learn.microsoft.com/en-us/answers/questions/2276373/how-to-create-a-vm-image-with-the-nvme-support?page=1&orderby=Helpful&comment=answer-2051602&translated=false#newest-answer-comment)

[r4victor]

Tested a staging VM image built with the NVME support on Standard_D2s_v6:

• ✅ Standard_D2s_v6
• ⛔️ Standard_A4_v2 – A series works only with Gen 1 images, so supporting it will require a separate VM image.
• ✅ Standard_D2s_v3 – Dsv3 works but can be dropped from dstack since it's retired and no cheaper than Dsv6.