Add support for uploading SystmOne vaccination records (#3327)

This updates the import process to allow users to upload a file in the
SystmOne format which has a different set of fields to the existing
format. We haven't got a real example of this type of file for testing,
so this is a best guess at how the format should be parsed.

We haven't updated any parts of the UI in this change, we might want to
do this in a follow up PR to describe the two different formats.

To build this, the import mechanism required a substantial refactor,
which is covered by:

- #3312
- #3317
- #3318
- #3325
- #3326

Author: thomasleese

app/lib/vaccination_description_string_parser.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+class VaccinationDescriptionStringParser
+  def initialize(string)
+    @string = string
+  end
+
+  def call
+    return nil if string.blank?
+
+    known_programme = KNOWN_PROGRAMMES.keys.find { string.starts_with?(it) }
+
+    programme_name = KNOWN_PROGRAMMES[known_programme]
+    return nil if known_programme.present? && programme_name.nil?
+
+    vaccine_name = (string.split(" ").first if known_programme.blank?)
+    return nil if known_programme.blank? && vaccine_name.blank?
+
+    dose_sequence_string =
+      if vaccine_name.present?
+        string[vaccine_name.length..]
+      elsif known_programme.present?
+        string[known_programme.length..]
+      end
+
+    dose_sequence =
+      begin
+        Integer(dose_sequence_string)
+      rescue ArgumentError, TypeError
+        dose_sequence_string&.strip&.presence
+      end
+
+    { programme_name:, vaccine_name:, dose_sequence: }.compact
+  end
+
+  def self.call(...) = new(...).call
+
+  private_class_method :new
+
+  private
+
+  attr_reader :string
+
+  KNOWN_PROGRAMMES = {
+    "Flu" => "Flu",
+    "HPV" => "HPV",
+    "Human Papillomavirus" => "HPV",
+    "MMR" => "MMR",
+    "Measles/Mumps/Rubella" => "MMR",
+    "MenACWY" => "MenACWY",
+    "Meningococcal conjugate A,C, W135 + Y" => "MenACWY",
+    "Td/IPV" => "Td/IPV"
+  }.freeze
+end