new icons for Kolibri 0.15

[indirectlylit]

Description

• add new Material and custom icons
• allow building just the custom icons
• fix extraction pattern

Issue addressed

fixes #260

Before/after screenshots

See deploy preview for full view

before	after

Steps to test

Compare with reference:

https://docs.google.com/document/d/1ahajDGXWR-Pym8ujBSXbXnw_7BOnYsB0O9TubabQRPg/edit

Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical and brittle code paths are covered by unit tests
• The change has been added to the changelog

Reviewer guidance

• Is the code clean and well-commented?
• Are there tests for this change?
• Are all UI components LTR and RTL compliant (if applicable)?
• Add other things to check for here

Post-merge updates and tracking

• Learning Platform update PR is submitted
• Learning Platform update PR is merged
• Studio update PR is submitted
• Studio update PR is merged
• Data Portal update PR is submitted
• Data Portal update PR is merged

Comments

[jtamiace]

Only missing icon seems to be 'skills' which got grouped with 'math'.
All the other icons & aliases look good!

[indirectlylit]

great, thanks.

Turned out that history was already a defined name so used a new section and convention for "Resource categories":

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