fix: change delete source commands and flags to sf style

[CristiCanizales]

What does this PR do?

• Updates Delete Source commands and flags to SF style in order to get rid of cli warnings

What issues does this PR fix or reference?

@W-14047399@

Changes

• force:source:delete ⇢ project:delete:source
• --sourcepath ⇢ --source-dir
• --noprompt ⇢ --no-prompt
• --tracksource ⇢ --track-source
• SFDX_JSON_TO_STDOUT ⇢ SF_JSON_TO_STDOUT

Warnings before

(node:90713) Warning: Deprecated environment variable: SFDX_JSON_TO_STDOUT. Please use SF_JSON_TO_STDOUT instead.
(Use `node —trace-warnings ...` to show where the warning was created)
Warning: The "force source delete" command has been deprecated. Use "project delete source" instead.
Warning: The "—sourcepath" flag has been deprecated. Use "—source-dir | -p" instead.
Warning: The "—noprompt" flag has been deprecated. Use "—no-prompt | -r" instead

Reference: https://developer.salesforce.com/docs/atlas.en-us.sfdx_cli_reference.meta/sfdx_cli_reference/cli_reference_force_source.htm#cli_reference_force_source_delete

[RitamAgrawal]

LGTM! Holding on to Approval. Let's merge it after the release

[RitamAgrawal]

Unused constants!

[RitamAgrawal]

🚢 Removed unused constants and imports.
Replacement of old sfdx with sf style cli-commands and renaming the variable names accordingly.