Rename package ObjectStore -> RustyObjectStore

[nickrobinson251]

To avoid name clash with already registered Julia packages.

JuliaRegistries/General#98486 (comment)

The following guidelines were not met:

• Package name similar to 1 existing package.
  • Similar to ObjectStores. Damerau-Levenshtein distance 1 is at or below cutoff of 2. Damerau-Levenshtein distance 1 between lowercased names is at or below cutoff of 1. Normalized visual distance 2.19 is at or below cutoff of 2.50.

Note that the guidelines are only required for the pull request to be merged automatically. However, it is strongly recommended to follow them, since otherwise the pull request needs to be manually reviewed and merged by a human.

Consensus on JuliaLang slack was that our package should change name... i don't mind what we call it, although i'd prefer it to have a name not too easily confused with CloudStore.jl

This is my proposal (whatever we decide, we then need to rename the repo too)