Fluid typography: use logarithmic scale factor to calculate a min font size

[ramonopoly]

Introduce logarithmic scale factor to calculate a minimum font scale that tapers out as the font size increases.

The current calculation that derives minimum font sizes from font sizes is linear, which means that very large font sizes won't be scaled down to a readable level.

Added to the Gutenberg plugin in ​https://github.com/WordPress/gutenberg/pull/49707

Slated for WordPress 6.3 and tracked in the backport issue: ​https://github.com/WordPress/gutenberg/issues/51077

Introduces logarithmic scale factor to calculate a minimum font scale that tapers out as the font size increases.

Added to the Gutenberg plugin in ​https://github.com/WordPress/gutenberg/pull/49707

Trac ticket: https://core.trac.wordpress.org/ticket/58523

## Testing

I've tested this using the 2023 theme.

In a new post, insert the following example block code. Play around with sizes and values.

<details>

<summary>Example block code</summary>

Loco brings you family recipes, fresh, simple, tasteful ingredients and a nice vibe.

---

A paragraph at 16rem

A paragraph at 8rem

A paragraph at 6rem

A paragraph at 4rem

A paragraph at 3rem

A paragraph at 2rem

A paragraph at 1rem

---

A paragraph at 256px

A paragraph at 128px

A paragraph at 96px

A paragraph at 64px

A paragraph at 48px

A paragraph at 32px

A paragraph at 16px

</details>

Run the tests!!

npm run test:php -- --filter Tests_Block_Supports_Typography

[isabel_brison]

In 55947:

Editor: use logarithmic scale for fluid typography.

Introduces logarithmic scale factor to calculate a minimum font scale that tapers out as the font size increases.

Props ramonopoly.
Fixes #58523.

Committed in r55947 / ​787de79.