Initial work on Vision support in text conversations and Image Editing

This is a huge patch which does some major refactoring like:

- renaming "Image Generation" to "Image Creation" in most places,
  to better match its new command (`!bai image create`)

- relocating image creation command (`!bai image` -> `!bai image create`),
  so it wouldn't conflict with the new image editing command (`!bai image edit`)

- introducing a new image editing command (`!bai image edit`), which
  is meant to work only with the OpenAI provider, but doesn't fully work yet
  due to https://github.com/64bit/async-openai/issues/364, though a next patch will fix it

- adding support for reading images off of Matrix conversations and forwarding them to
  text conversations. Works for OpenAI, but not for Anthropic yet
  (requires custom patches) and not for OpenAI-Compat (no support for
  images there)

- relocating some utils around (base64, mime)

docs/configuration/README.md

@@ -40,7 +40,7 @@ You can adjust the following settings per room and/or globally:
 - [💬 Text Generation](text-generation.md)
 - [🦻 Speech-to-Text](speech-to-text.md)
 - [🗣️ Text-to-Speech](text-to-speech.md)
-- [🖌️ Image Generation](image-generation.md)
+- [🖌️ Image Creation](image-generation.md)
 - [🤝 Handlers](handlers.md)
 
 Refer to the bot's help messages (as a response to a `!bai config` help command) for the most up-to-date information on what Room Settings can be configured.

docs/configuration/handlers.md

@@ -11,7 +11,7 @@ The bot supports the following use-purposes:
 - [💬 text-generation](../features.md#-text-generation): communicating with you via text
 - [🦻 speech-to-text](../features.md#-speech-to-text): turning your voice messages into text
 - [🗣️ text-to-speech](../features.md#️-text-to-speech): turning bot or users text messages into voice messages
-- [🖌️ image-generation](../features.md#-image-generation): generating images based on instructions
+- [🖌️ image-generation](../features.md#image-generation): generating images based on instructions
 
 In a given room, each different purpose can be served by a different [provider](../providers.md) and model. This combination of provider and model configuration is called an [🤖 agent](../agents.md). Each purpose can be served by a different **handler** agent.
 

docs/configuration/image-generation.md

@@ -1,9 +1,11 @@
 
-## 🖌️ Image Generation
+## Image Generation
 
-The Image Generation feature is not configurable at this moment.
+The Image Creation and Image Editing features are not configurable at this moment.
 
 You may also wish to see:
 
-- [🌟 Features / 🖌️ Image Generation](../features.md#-image-generation) for a higher-level introduction to the Image Generation features
-- [📖 Usage / 🖌️ Image Generation](../usage.md#-image-generation) section for more details on how to use the bot for Image Generation in a room
+- [🌟 Features / Image Generation / 🖌️ Image Creation](../features.md#-image-creation) for a higher-level introduction to the Image Creation features
+- [🌟 Features / Image Generation / 🎨 Image Editing](../features.md#-image-editing) for a higher-level introduction to the Image Editing features
+- [📖 Usage / Image Generation / 🖌️ Creating Images](../usage.md#-creating-images) section for more details on how to use the bot for Image Creation in a room
+- [📖 Usage / Image Generation / 🎨 Editing images](../usage.md#-editing-images) section for more details on how to use the bot for Image Editing in a room