Rename "content connectors" to "content crawler"

**Short description:** Rename the connector terminology used in the `elastic_connectors` package (and related catalogue references) from "content connectors" to "content crawler" for clarity and consistency.

Affected connectors (as currently listed in `packages/elastic_connectors/manifest.yml`):

| # | Connector Name (internal `name`) | Title as shown in Integrations Catalogue |
|---|---|---|
| 1 | github | GitHub & GitHub Enterprise Server Connector |
| 2 | google_drive | Google Drive Connector |
| 3 | gmail | Gmail Connector |
| 4 | azure_blob_storage | Azure Blob Storage Connector |
| 5 | box | Box Connector |
| 6 | confluence | Confluence Connector |
| 7 | dropbox | Dropbox Connector |
| 8 | google_cloud_storage | Google Cloud Storage Connector |
| 9 | jira | Jira Connector |
| 10 | microsoft_sql | Microsoft SQL Connector |
| 11 | mongodb | MongoDB Connector |
| 12 | mysql | MySQL Connector |
| 13 | network_drive | Network Drive Connector |
| 14 | notion | Notion Connector |
| 15 | onedrive | OneDrive Connector |
| 16 | oracle | Oracle Connector |
| 17 | outlook | Outlook Connector |
| 18 | postgresql | PostgreSQL Connector |
| 19 | amazon_s3 | Amazon S3 Connector |
| 20 | salesforce | Salesforce Connector |
| 21 | sandfly | Sandfly Security Connector |
| 22 | servicenow | ServiceNow Connector |
| 23 | sharepoint_online | SharePoint Online Connector |
| 24 | sharepoint_server | SharePoint Server Connector |
| 25 | slack | Slack Connector |
| 26 | teams | Teams Connector |
| 27 | zoom | Zoom Connector |

Source: `packages/elastic_connectors/manifest.yml`

Start with packages/elastic_connectors/manifest.yml, which lists the affected connectors, then search the elastic_connectors package and related catalogue references for the phrase "content connectors." The work is done when the relevant terminology consistently uses "content crawler" while the listed internal connector names remain unchanged.

Written by the indexing model from the issue text.