Revert "Changes to wording for download button and estimator"

This reverts commit 71a4fe20cd4640c3e4cddd6c4c148cb6a9084e6a.
Revert "Merge pull request #911 from aodn/dl_estimate_final_fix"

This reverts commit f53ac80621400ea97b2d068c526457a245025084, reversing
changes made to 78cd0272ca941ddf66a04015b53f3d10ebe98bdd.