QuickBooks source connector - Change naming

[igrankova]

Tell us about the problem you're trying to solve

We need to update naming to correct one in all places where it's mentioned in the connector and docs according to the QuickBooks requirements for OAuth Public applications.

Describe the solution you’d like

Naming update in docs and app
Current name: Quickbooks

Should be: QuickBooks

1. In the source type:
   

2. In our docs we have incorrect naming everywhere:
   on our web site: https://airbyte.com/connectors/quickbooks
   and in the docs: https://docs.airbyte.com/integrations/sources/quickbooks

3. Update Docs link.

[EPIC] Implement QuickBooks requirements to list App on a Marketplace #10264

[igrankova]

Updated