Implement query to assess opportunity to fix sites that have lazy-loaded LCP image

[felixarntz]

This query is related to and based on #45.

Query results

Note that this is the % only relative to the sites that have an image as the LCP element. It is not relative to the total number of WordPress sites.

Row	client	lazy_loaded_lcp	total_lcp	pct_lazy_loaded
1	desktop	369675	1686728	0.21916693147917152
2	mobile	440164	2058102	0.21386889473893908

Based on February 2023 dataset

For reference, the total number of WordPress sites in that month is 3,975,233 on desktop, 5,383,714 on mobile. This means that combined with the above results, 42.4% of sites on desktop, 38.2% of sites on mobile have an image as their LCP element.