ARROW-15819: [R] R docs version switcher doesn't work on Safari on MacOS

[thisisnic]

Updates the code used in the version switcher to be compatible with Safari, and adds extra docs to the version switcher.

Recommendations for reviewing this PR:

• You could try building the pkgdown site locally, but the problem there is that the code for constructing the URLs for the dropdown doesn't actually work when loading the page from a file like that
• What I do is navigate to a deployed page (I used https://arrow.apache.org/docs/3.0/r/ as there is no version dropdown on that version of the docs) and then open us the JS console in my browser and copy and paste the contents of extra.js into there - you'll then see the dropdown appear and can check the links point to the correct places
• The thing we want to check for on this PR is that the dropdown is generated in Safari on MacOS - it wasn't before due to an incompatible regex

[github-actions]

https://issues.apache.org/jira/browse/ARROW-15819

[github-actions]

⚠️ Ticket has not been started in JIRA, please click 'Start Progress'.

[AlenkaF]

Checked the dropdown in Safari on my M1 and it works well 👍

Ran the JS code

Selected the dev version

Had to screenshot the dropdown menu separately =)

[dragosmg]

I can confirm the dropdown works on my machine (M1 Mac) too.

[thisisnic]

Thanks @AlenkaF and @dragosmg for testing this!

[ursabot]

Benchmark runs are scheduled for baseline = ab55bba and contender = aa2e8da. aa2e8da is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Finished ⬇️0.21% ⬆️0.0%] test-mac-arm
[Failed ⬇️0.0% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.04% ⬆️0.0%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ec2-t3-xlarge-us-east-2/builds/491| aa2e8da8 ec2-t3-xlarge-us-east-2>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-test-mac-arm/builds/476| aa2e8da8 test-mac-arm>
[Failed] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ursa-i9-9960x/builds/477| aa2e8da8 ursa-i9-9960x>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ursa-thinkcentre-m75q/builds/486| aa2e8da8 ursa-thinkcentre-m75q>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ec2-t3-xlarge-us-east-2/builds/490| ab55bbad ec2-t3-xlarge-us-east-2>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-test-mac-arm/builds/475| ab55bbad test-mac-arm>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ursa-i9-9960x/builds/476| ab55bbad ursa-i9-9960x>
[Finished] <https://buildkite.com/apache-arrow/arrow-bci-benchmark-on-ursa-thinkcentre-m75q/builds/485| ab55bbad ursa-thinkcentre-m75q>
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java