Add GetInvoices code example (#456)
Add GetInvoices code example (#456)

* Add code GetInvoices example

Change-Id: I2bff0558c7315ad7196b1f12a3fb0ea5bc035ac9

* Implement the printing block

Change-Id: Ia2bd2b2936d58659754722d8a1285e824053baa4

* Few fixes

Change-Id: I3943d3f0807253e55552e384a73fe8ade1b4a911

* Integrate with V6

Change-Id: I62d3ad33959a064137dd4fbef99be8bf28dcad4b

* Added PDF references and added extra logic for fields that may be unset

Change-Id: Id788f6fdd4c4ecf6eb3e723b945d28975d527682

* Add region tags for guide

Change-Id: Id400f868503985c8780c6f37613d5b5deaabea37

* Code style fix

Change-Id: I06343b1f6b6849d40c187124f6fdb4d7c69a561f

* Added single quotes in prints for clarity

Change-Id: I50750857b38806d9d9badbce28b795941f0d9b2b

* Change from plain unit to base unit wording

Change-Id: I230d776a01d70b08041129ff56d37de4f765ca0a

Co-authored-by: pierrick <df474784b32dd401bcc15bd466f2f639c8ded6ef@google.com>
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