Browser support update

We try to update the supported browser list around the end of the year.
This year, I'm a little early in doing some analysis, but here we go.

The currently (according to the FAQ at https://www.pgadmin.org/faq) support
the following browsers:

Chrome 72+
Firefox 65+
Edge 44+ (reported as 18+ by Google Analytics)
Safari 12+

I took a look at the Google Analytics data for the website and see the
following browser usage distribution. There are more, but they're all < 1%:

Browser pgAdmin
======= =======
Chrome 69.75%
Firefox 13.01%
Edge 7.93%
Safari 5.45%
IE 1.53%
Opera 1.22%

We've already dropped support for IE (which I don't want to see
resurrected), and Opera should work fine as it's based on Chromium's Blink
engine, so whilst we don't test it explicitly, we should respond to any
issues reported.

Digging more into the details:

Chrome
======

94.1% of users are running Chrome 85+

Firefox
=====

83.95% of users are running Firefox 80+. However, 6.84% run Firefox 78.0,
2.12% run Firefox 68.0, and 1.6% run Firefox 79.0. Perhaps these outliers
are versions that shipped with major OS releases and haven't been updated?

Edge
====

Much more varied usage, complicated by the change in versioning (and the
engine), when the version number went from 18 (Spartan releases) to 79
(Anaheim releases), as reported by Google Analytics. In the top 10
versions, 79.24% of users are running 86+. However, the top 10 also
includes 11.94% running 18.x and 1.55% running 17.x. This is likely from
corporate environments where updates are controlled in a conservative
manner.

Safari
=====

Mixed usage. From the top 10, 83.68% use 13+. However, 8.65% use 9.0, and
1.84% use 12.1.2. There are also 2.03% using 538.1 (probably Epiphany).

Based on these numbers, I would suggest we test and support the following
browsers from the first release in 2021:

Chrome: 85+
Firefox: 78+ (this would exclude the 2.12% running 68, but as they're
likely not updating their software anyway it likely won't matter)
Edge: 44, and 86+ (44 is the last Spartan release. The vast majority of
users on the Anaheim release are on 86+).
Safari: 13+

Thoughts/comments/objections?

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EDB: http://www.enterprisedb.com