Issue #1360: ITS Filter: the exposition of XLIFF maxwidth and size-unit trans-unit attributes has to be supported (okapiframework/okapi)

[DenisKonovalyenko]

New issue 1360: ITS Filter: the exposition of XLIFF maxwidth and size-unit trans-unit attributes has to be supported
https://bitbucket.org/okapiframework/okapi/issues/1360/its-filter-the-exposition-of-xliff

Denis Konovalyenko:

Currently, the ITS filter supports related `storageSizeRule` attributes but their values can't be mapped to the standard attributes in XLIFF - `maxwidth` and `size-unit`.

For instance, for the document:

```xml
<?xml version="1.0" encoding="UTF-8"?>
<root>Maximum</root>
```

and applied ITS rules:

```xml
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<its:rules xmlns:its="http://www.w3.org/2005/11/its" xmlns:itsx="http://www.w3.org/2008/12/its-extensions" xmlns:okp="okapi-framework:xmlfilter-options" xmlns:xlink="http://www.w3.org/1999/xlink" its:translate="no" version="1.0">
<its:storageSizeRule selector="//root" storageSize="7"/>
</its:rules>
```

the following textual unit extraction in XLIFF would be expected:

```xml
<trans-unit id="1" maxwidth="7" size-unit="char">
<source xml:lang="en">Maximum</source>
<target xml:lang="fr"></target>
</trans-unit>
```

Also, the `includeITS` XLIFF writer parameter behaviour should remain the same.

For more details please look at the attachments.