FIX: Installer language pack warning

[carlwilson]

• changed Welcome panel to be a Hello panel and resized;
• added default language pack files to mute installer warning; and
• added OPF copyright to LICENCE.

Closes #845

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (28f8541) 47.00% compared to head (382a3bc) 47.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## integration #851 +/- ## ============================================== Coverage 47.00% 47.00% Complexity 1100 1100 ============================================== Files 57 57 Lines 9079 9079 Branches 1622 1622 ============================================== Hits 4268 4268 Misses 4280 4280 Partials 531 531 ```

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