Extract js-api methods into seperate file

Description

This PR refactors server-related functions in the client code by moving them into the js/api/ApiProvider.js component.

Also:

Enhanced sendPaneMessage and sendEmbeddingPop by adding targetId and envID as arguments, making the code more versatile for pane-functions that trigger server messages when not selected. However, no changes in user functionality have been made.
Replaced all "raw" sendSocketMessage calls with specialized versions for improved code readability and maintainability.
Renamed communication functions for better semantics and consistency:
- sendX: Functions send data or queries to the server. Normalized naming to sendNounVerb for an improved autocompletion experience.
- onX: Functions that are called when the server sends something to the client, aligning with event naming conventions.

Motivation and Context

The aim was to enhance code readability and reduce the lines of code in main.js. Using useContext has simplified the use of API functions in child components. Previously, these functions needed to be forwarded in the JSX calls, but now they can be accessed globally.

How Has This Been Tested?

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Screenshots (if appropriate):

Types of changes

[ ] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[x] Code refactor or cleanup (changes to existing code for improved readability or performance)

Checklist:

[ ] I adapted the version number under py/visdom/VERSION according to Semantic Versioning
[x] My code follows the code style of this project.
[ ] My change requires a change to the documentation.
[ ] I have updated the documentation accordingly.

fossasia / visdom

Extract js-api methods into seperate file #918