Spell List Refactor (making spell creation easier)

[stoneharry]

Make spell creation a lot easier by improving the spell selection list.

Issue: #206

• Make Spell Selection List a component
• Update new spell to not do a full rebuild of the list
• Update delete spell to not do a full rebuild of the list
• Implement context menu support for spell selection list
• Implement delete spell context menu
• Implement copy spell context menu
• Implement duplicate spell context menu
• Remove new/delete spell buttons from window header (might want to keep this)
• Localise strings

Also priotitises the spell DBC import/export when selected in the UI by using the existing DB adapter.