Fix Docker build versioning (#20077)

* Centralise version scripts and fix Docker version
* Refactor generation of a git-hash-based version into get-version-from-git
* Refactor normalization of versions (stripping leading v) into normalize-version.sh
* Call get-version-from-git from ci_package.sh, call normalize-version from package.sh
* Refactor docker-write-version.sh into docker-package.sh, which both writes the
  version file and invokes yarn build passing VERSION
* Normalize the version received from the server

scripts/normalize-version.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# If $1 looks like v1.2.3 or v1.2.3-foo, strip the leading v, then print it to stdout
+if [[ $1 =~ ^v[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+(-.+)?$ ]]; then
+    echo ${1:1}
+else
+    echo $1
+fi