Add inscription field to tourism=artwork

[kjonosm]

Description, Motivation & Context

Common combination, see https://taginfo.openstreetmap.org/tags/tourism=artwork#combinations

Related issues

closes #1635

Links and data

Relevant OSM Wiki links:

https://wiki.openstreetmap.org/wiki/Key:inscription
https://wiki.openstreetmap.org/wiki/Tag:tourism%3Dartwork

Relevant tag usage stats:

https://taginfo.openstreetmap.org/tags/tourism=artwork#combinations

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## Test-Documentation

### Preview links & Sidebar Screenshots

<!-- Use the preview to find examples, select the feature in question and **copy this link here**.
     Find examples of nodes/areas. Find examples with a lot of tags or very few tags. – Whatever helps to test this thoroughly.
     Add relevant **screenshots** of the sidebar of those examples. -->

<!-- FYI: What we will check:
     - Is the [icon](https://github.com/ideditor/schema-builder/blob/main/ICONS.md) well chosen.
     - Are the fields well-structured and have good labels.
     - Do the dropdowns (etc.) work well and show helpful data. -->

### Search

<!-- **Test the search** of your preset and share relevant **screenshots** here.
     - Test the preset name as search terms.
     - Also test the preset terms and aliases as search terms (if present). -->

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     [Learn more…](https://github.com/openstreetmap/id-tagging-schema/blob/main/CONTRIBUTING.md#info-i)
 -->

### Wording

- [ ] American English
- [ ] `name`, `aliases` (if present) use Title Case
- [ ] `terms` (if present) use lower case, sorted A-Z
<!-- Learn more in https://github.com/openstreetmap/id-tagging-schema/blob/main/GUIDELINES.md#2-design-the-preset -->

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[kjonosm]