chore(mac): update to SIL logo with glyph in About window

[sgschantz]

Change About window from this:

to this:

Note that the new logo used is Andika v1 from: https://sites.google.com/sil.org/brand-resource-center/branding/visual-brand/logos

Fixes: #12159

User Testing

• TEST_ABOUT_WITH_SIL_LOGO: verify new SIL logo appearance

1. Install and run the Keyman build associated with this PR
2. Verify that the About window displays the updated SIL logo with accompanying glyph

[keymanapp-test-bot]

User Test Results

Test specification and instructions

• ✅ TEST_ABOUT_WITH_SIL_LOGO (PASSED) (notes)

Test Artifacts

• macOS
  • Keyman for macOS

[mcdurdin]

to this:

The stripes are supposed to be a thin band -- see keyman.com, and the logo is supposed to be on a white background, otherwise it is lost against the orange. See the design guide on the Google drive: https://drive.google.com/file/d/11Hqm9EeEnY6EEOxALTRbSLz5poLc6FRH/view?usp=drive_link

[sgschantz]

Now updated to so that the three-color stripe is a thin band 7 points in height.
It was apparently incorrect when running under Sonoma or later due to the Sonoma change in macOS where the default setting in UIView for (the formerly internal value) clipsToBounds changed from true to false.

Here is the updated appearance:

[mcdurdin]

Here is the updated appearance:

That looks great, thanks!

[dinakaranr]

Test Results

I tested this issue with the attached "Keyman 18.0.151-alpha-local" build on macOS Sonoma 14.5. 

• TEST_ABOUT_WITH_SIL_LOGO (Passed):

1. Install the "Keyman 18.0.151-alpha-local" build.
2. Installed the "Khmer" & "Tamil99" keyboards.(e.g., IPA SIL)
3. Select the "Khmer" keyboard.
4. Open the "About" window by clicking the keyman icon.
5. Verified the keyman logo appears as per the design doc. 
6. Verified the Keyman logo has a white background on the header. 
7. Verified the keyman links and buttons work on the About window.
   It works well. Thank you.

[keyman-server]

Changes in this pull request will be available for download in Keyman version 18.0.154-alpha