QuickSight: Proper Analysis or Template CDK Construct

### Description

Currently, the only way to create a QuickSight::Analysis is by giving it a QuickSight::Template as sourceEntity.
And the only way to create a QuickSight::Template is by giving it either a QuickSight::Template or a QuickSight::Analysis as source Entity.
So it is impossible to automate the creation of the Analysis completely.

### Use Case

We want to reduce manual steps when deploying our pipeline as much as possible. We also want to version control the visuals in our analysis.

### Proposed Solution

To properly automate QuickSight with CDK we need a way to define the Template with CDK, by perhaps passing it a json with the definition of all visuals in the analysis. This way we can source control the Analysis design and eliminate the manual steps for creating the analysis in the console.

Ideally there would be a way to call aws-describe-template to see the json of an analysis created with the console manually, that can then be included in the CDK src.

### Other information

_No response_

### Acknowledge

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

Review the existing QuickSight::Analysis and QuickSight::Template CDK constructs, then compare their sourceEntity requirements with the QuickSight APIs described in the issue. Investigate whether aws-describe-template exposes the needed analysis definition and determine the construct and validation scope required for a fully reproducible analysis. Done means the feature works without a manually created source analysis and supports version-controlled definitions.

Written by the indexing model from the issue text.