ti_google_threat_intelligence: Set destination pipeline name automatically in transforms

Due to an earlier limitation of elastic-package to unable to extract
integration version into the transform, the destination pipeline 
needed to be set/updated manually.

Currently the integration requires users to manually add destination 
pipelines into the transform during the package installation and 
upgrade. This presents significant inconvenience to users and is 
often error-prone.

elastic-package#2973 [1] removes the dest pipeline limitation 
which now allows the pipeline names to be templated. This PR
updates the transform definition to set the pipeline names using 
a template which renders integration version.
Change involves updating all transforms with:
dest:
  pipeline: '{{ ingestPipelineName "<pipeline-name>"}}'

Also:
- With this the transform's does not require any manual 
intervention, hence they are now auto-enabled.
- README is updated accordingly.

[1] https://github.com/elastic/elastic-package/pull/2973

--- Test results for package: ti_google_threat_intelligence - START ---
╭───────────────────────────────┬─────────────┬───────────┬───────────┬────────┬──────────────╮
│ PACKAGE                       │ DATA STREAM │ TEST TYPE │ TEST NAME │ RESULT │ TIME ELAPSED │
├───────────────────────────────┼─────────────┼───────────┼───────────┼────────┼──────────────┤
│ ti_google_threat_intelligence │ cryptominer │ system    │ default   │ PASS   │  45.2311125s │
╰───────────────────────────────┴─────────────┴───────────┴───────────┴────────┴──────────────╯
--- Test results for package: ti_google_threat_intelligence - END   ---
Done