feat: migrate block definitions to getConfig

[Swanand01]

What

This PR moves the custom block definitions to the snapwp.config.mjs file.
Instead of passing them as props to the EditorBlockRenderer, they are now imported from getConfig

Why

Since block definitions are overloadable/configurable, they should be put in the snapwp.config.mjs file.

Related Issue(s):

https://github.com/orgs/rtCamp/projects/141/views/14?pane=issue&itemId=96524753&issue=rtCamp%7Cheadless%7C396

How

SnapWPConfig is updated to include blockDefinitions, and an example CoreQuote implementation is passed in snapwp.config.mjs

Testing Instructions

Screenshots

Additional Info

Checklist

• I have read the Contribution Guidelines.
• My code is tested to the best of my abilities.
• My code passes all lints (ESLint, tsc, prettier etc.).
• My code has detailed inline documentation.
• I have added unit tests to verify the code works as intended.
• I have updated the project documentation accordingly.

[Swanand01]

@ayushnirwal @justlevine What kind of validation should we add here:

snapwp/packages/core/src/config/snapwp-config-manager.ts

Lines 200 to 203 in be538ae

	blockDefinitions: {
	type: 'object',
	required: false,
	},

[Swanand01]

@justlevine Do we want to enforce lazy loading for the custom block implementations, or do we leave it up to the user to use React.lazy / normal imports?

On a side note, I haven't been able to verify if using React.lazy while passing block definitions is working as intended. Have discussed the same with @ayushnirwal over a call.

[Swanand01]

This is blocked because we cannot import .tsx block definition files into snapwp.config.mjs.
The PR will be unblocked when we move snapwp.config to .ts

cc: @BhumikP