Add download stats and release dates to mix hex.info

[s3cur3]

This adds download counts and release dates (provided by hex.pm/api/packages/[package_name]) to the mix hex.info [package_name] and mix hex.info [package_name] [version] commands.

Download counts for the overall package info include yesterday, last 7 days, and all-time.

Two decisions I'm not entirely sure of, but happy to revisit:

• Showing the download numbers for the current version (like the Hex.pm website does) would require a second HTTP request, which seemed iffy.
• I wasn't clear on what the "recent" key in the downloads meant (it looks like it might be the last 8 releases?), so I left that out of the download output since I was unable to give a more concrete label for it.

(The formatting on the before/after table below is a little weird... GitHub seems to be adding additional spaces between "paragraphs.")

Resolves #1128

Before	After
$ mix hex.info jason A blazing fast JSON parser and generator in pure Elixir. Config: {:jason, "~> 1.4"} Locked version: 1.4.4 Releases: 1.5.0-alpha.2, 1.5.0-alpha.1, 1.4.4, 1.4.3, 1.4.2, 1.4.1, 1.4.0, 1.3.0, ... Licenses: Apache-2.0 Links: GitHub: https://github.com/michalmuskala/jason	$ mix hex.info jason A blazing fast JSON parser and generator in pure Elixir. Config: {:jason, "~> 1.4"} Releases: 1.5.0-alpha.2 (2023-07-07), 1.5.0-alpha.1 (2022-10-16), 1.4.4 (2024-07-26), 1.4.3 (2024-06-29), 1.4.2 (2024-06-29), 1.4.1 (2023-07-07), 1.4.0 (2022-09-12), 1.3.0 (2021-12-21), ... Downloads: Yesterday: 20120 Last 7 days: 362042 All time: 196976983 Licenses: Apache-2.0 Links: GitHub: https://github.com/michalmuskala/jason
$ mix hex.info jason 1.5.0-alpha.2 Config: {:jason, "~> 1.5.0-alpha.2"} Documentation at: https://hexdocs.pm/jason/1.5.0-alpha.2 Dependencies: decimal ~> 1.0 or ~> 2.0 (optional) jason_native >= 0.0.0 (optional) Published by: michalmuskala (michal@muskala.eu)	$ mix hex.info jason 1.5.0-alpha.2 Config: {:jason, "~> 1.5.0-alpha.2"} Released: 2023-07-07 Documentation at: https://hexdocs.pm/jason/1.5.0-alpha.2 Downloads: 25694 Dependencies: decimal ~> 1.0 or ~> 2.0 (optional) jason_native >= 0.0.0 (optional) Published by: michalmuskala (michal@muskala.eu)