Parametrizing application name for more flexibility

[PrantikTechie]

resolves #
docs dbt-labs/docs.getdbt.com/#

Problem : As per the current implementation, the application name is hard coded to "dbt". But as per some use cases, it might require some custom application name.

Solution : Making the application name parametrized. Whatever value the user will pass as query tag that will be considered as application name.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

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[PrantikTechie]

Closing this pull request due to some reasons.