docs(node): restruct the snap sync

[jsvisa]

Description

closes #1772

What have done:

1. Restructured node-operators/guides/management/snap-sync.mdx, split the archive and consensus sync into seperated pages
2. Created a new page in node-operators/reference/features/snap-sync.mdx, which is focused on how is the snap sync working and the benefits.

Tests

Additional context

Metadata

[jsvisa]

@sbvegan PTAL