This adds History.Helpers.get_text_data() helper to fetch contents of a
"text" message. This removes the need to know internals of message
structure outside of history module.
When updating chat history to be used in LLM request there are several
instances where we do O(n^2) operations: scanning all messages to locate
a tool "use" and for each use scan messages again to locate
corresponding "result".
Refactor the code to scan messages once collecting tool uses and results
together, and then do 2nd scan to drop incomplete tool invocations and
refresh "view" and "edit" results with the latest content.
Also reduce number of pre-scan loops (where we discard partially
generated messages or messages that are not interesting or too-old) by
combining them when possible.
This reduces time to scan initial 417 messages on my system (which
result in 576 final messages) from 0.32 to 0.12 seconds.
There are many places in the code that wants to work with content of
"tool use" and "tool result" messages. Currently such code uses
is_tool_use_message() and is_tool_result() message to check if message
is of right kind, and then pokes into message internals. This is not
very efficient.
Introduce get_tool_use_data() and get_tool_result_data() that would
return contents of the message if it is of right kind, or nil otherwise.
Also introduce get_tool_result() that attempts to locate result of a
tool execution by its invocation ID.
The utils module has grown too big and contains unrelated functionality.
Start moving code related to managing history messages comprising chat
history into lua/avante/history module to keep the code more manageable.
