ENSAwards date range environment variables

[Goader]

Background:

• ENS Holiday Awards needs a "Referrer Detail" page, that will display the referrals statistics for a given address.
• Follows feat: introduce ENSAnalytics API into ENSApi #1239
• ENS Holiday Awards launch is Dec 1st, and we need to be able to test it properly before that date.

Subtasks:

• Introduce two new environment variables to ENSApi (ENSAWARDS_START and ENSAWARDS_END), defining the date range for the ENSAnalytics
• If no environment variables are defined, then the default value for ENSAWARDS_START is "Dec 1, 2025 00:00:00 UTC", and for ENSAWARDS_END - "Dec 31, 23:59:59 UTC".