Refactor formatKeyName function for better reusability and structure

[coderabbitai]

Proposal

Based on discussion in PR #663, there are two potential improvements to the formatKeyName function in components/odh-notebook-controller/controllers/notebook_runtime.go:

1. Move .json suffix addition up in the call chain

Currently, the .json suffix is added within the formatKeyName function. The proposal is to:

• Remove the .json suffix from formatKeyName
• Add it at the call site: data[formattedName + ".json"] = metadataParsed

2. Rename function for better reusability

Rename formatKeyName to sanitizeName to make it more generic and potentially reusable in other parts of the codebase.

Benefits

• Separation of concerns: the sanitization logic is separate from the specific .json suffix requirement
• Better reusability: a generic sanitizeName function could be used elsewhere
• Clearer intent: the function name would better reflect its generic sanitization purpose

References

• Original discussion: Improve formatKeyName function to handle all invalid ConfigMap key characters #663 (comment)
• Related PR: Improve formatKeyName function to handle all invalid ConfigMap key characters #663

Requested by: @jstourac