fix TCFv2 vendor list request

[katie-ta]

Summary

Fix request to fetch the TCF Vendor List to work with TCFv2.

• update vendor list URL: https://vendor-list.consensu.org/v${vendorListVersion}/vendor-list.json
• update vendor list version #
  • note that previous versions of the list are not publicly accessible

Other small updates:

• make everything camelCase for style purposes
• rename "vendorlist" to "vendorList"

Test

kind of hacked a test, since the rest of the extension isn't working;

• called loadVendors() directly
• printed out output of request and verified it contained vendor list information:

Reviewers

@charles-tan

[katie-ta]

moved this function to be be defined after showVendors since it calls showVendors