auto: increment master version to 15.0.65

fix(linux): Fix packaging on ppa

When building packages on ppa the TERM environment variable is set
to "unknown", which isn't a valid value but which we didn't account
for previously.

refactor(common/core/web, web): target-agnostic key events

fix(oem/fv/ios): app encryption flag for app store uploads (15.0)

feat(android): Automatically install keyboard through Play Store

auto: increment master version to 15.0.64

fix(android/engine): Adjust default OSK landscape size

fix(windows): support Esc key in Download Keyboard dialog

chore(common): iis setup script for dev boxes

fix(web): Always pass kill_browserstack

feat(common): Rust infrastructure

Resolves #5219.

Uses the Google Play Install Referrer API to automatically discover the
keyboard to install together with Keyman; this keyboard is passed in a
`referrer` parameter to the Play Store page for the Keyman app from the
Keyman website.

auto: increment master version to 15.0.63

fix(developer): support spaces in regression tests

auto: increment master version to 15.0.62

feat(linux): Integrate with fcitx5

fix(linux): Exclude s390x from package builds for ibus-keyman

Co-authored-by: Marc Durdin <marc@durdin.net>

Fixes #5216.

A `<text>` element in the regression text xml which contained only
whitespace would cause the import to crash as this would be ignored by
the XML parser, leading to a `Null` `nodeValue` for that element. To
solve this, we need to:

1. Use `xml:space="preserve"` attribute on `<text>` elements
2. Update the DTD to allow `xml:space` on `<text>` elements
3. While we are at it, move the DTD from `www.tavultesoft.com` to
   `api.keyman.com`.

See also:
* keymanapp/tavultesoft.com#4
* keymanapp/api.keyman.com#155

This change implements the Keyman side of the fcitx5 integration.
Closes #4910.

Part of #4910.