Should we deprecate `[verb]Blobentry[!]` in favour of explicit `[verb]VariableBlobentry[!]`?

[Affie]

For historic reasons — variables were the only nodes that had blob entries — we had [verb]Blobentry instead of [verb]VariableBlobentry. In a call on NavAbility/NavAbilitySDK.jl#298, @dehann said that should no longer be the case. I couldn't find the decision written down, so opening this issue to formalize it and avoid any possible miscommunication. After looking at the implementation, I agree.

The reason to not have addBlobentry! == addVariableBlobentry!:

• Julia’s multiple dispatch allows generic addBlobentry!(node, entry) to work, but other languages may not support this pattern; explicit names like addVariableBlobentry! are encouraged for multi-language use.
• We can export addVariableBlobentry! for API stability and clarity, while keeping addBlobentry! public for advanced Julia users (see discussion).
• This separation helps avoid accidental misuse, especially with by-reference mutations.
• Variables do not receive special treatment; applying the same explicit naming pattern (e.g., getFactorBlobentry, getVariableBlobentry) across all node types makes the API more consistent and intuitive for users.

The same logic will be implemented in [verb]Bloblet[!] (although, no deprecation is needed as it is new functions).