[Bug] /api/v1/search/ - channel thumbnails are the same size

[brunteless]

Describe the bug
During the writing of #4895, I noticed that the URLs are all identical the common image has size of 88 pixels, while the response reports 32, 48, 76, 100, 176, 512 pixels. This doesn't appear to be the case with the /api/v1/channels/:id endpoint.

Steps to Reproduce

1. Go to https://your-instance-of.choice/api/v1/search?q=known-channel
2. Find the given channel
3. Scroll down to the authorThumbnails list
4. Compare the thumbnails and their links

Example
Search result consistent across multiple public API instances:

[  
   {  
       "type": "channel",  
       "author": "MrBeast",  
       "authorId": "UCX6OQ3DkcsbYNE6H8uQQuVA",  
       "authorUrl": "/channel/UCX6OQ3DkcsbYNE6H8uQQuVA",  
       "authorVerified": true,  
       "authorThumbnails": [  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 32,  
               "height": 32  
           },  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 48,  
               "height": 48  
           },  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 76,  
               "height": 76  
           },  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 100,  
               "height": 100  
           },  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 176,  
               "height": 176  
           },  
           {  
               "url": "//yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 512,  
               "height": 512  
           }  
       ]  
   },
   ...  
]

Possible Fix
Either the use of the same logic that powers the /api/v1/channels/:id endpoint or a simple adjustment in the search response, similar to this one:

[  
   {  
       "type": "channel",  
       "author": "MrBeast",  
       "authorId": "UCX6OQ3DkcsbYNE6H8uQQuVA",  
       "authorUrl": "/channel/UCX6OQ3DkcsbYNE6H8uQQuVA",  
       "authorVerified": true,  
       "authorThumbnails": [  
           {  
               "url": "https://yt3.ggpht.com/fxGKYucJAVme-Yz4fsdCroCFCrANWqw0ql4GYuvx8Uq4l_euNJHgE-w9MTkLQA805vWCi-kE0g=s88-c-k-c0x00ffffff-no-rj-mo",  
               "width": 88,  
               "height": 88  
           }  
       ]  
   },
   ...  
]

Note
These are my first two bug reports ever, so I have no idea what I'm doing. If I've done something wrong, please don't hesitate to correct me.