Adds filtering to expressions to ignore labels that do not have sprites available

[Wolfsblvt]

• Functionality only available for LLM/webLLM
• New toggle to filter expressions on availalbe sprites
• getExpressionsList filters cached expressions when checked (using sprite folder name/override)
• /expression-list slash command has "filter" arg to filter list
• /expression-classify slash command has "filter" arg now, to use filtered list for classification
• getExpressionLabel uses filtered expressions when LLM/webLLM

Closes #3696

Checklist:

• [x] I have read the Contributing guidelines.

Copilot

This pull request introduces several enhancements to the expressions module in the public/scripts/extensions/expressions/index.js file. The primary focus is on adding a filtering option for expressions, allowing users to filter expressions based on the availability of sprites.

Key changes include:

Enhancements to Expression Filtering:

• Added isTrueBoolean utility function to import statement to support new filtering logic.
• Introduced a new filter parameter to the classifyCallback function and updated its usage within the function to check for filter availability. [1] [2]
• Updated the getExpressionLabel function to include a new filterAvailable option, and added logic to handle filtering based on the availability of sprites. [1] [2] [3] [4]
• Modified the getExpressionsList function to accept a filterAvailable parameter and filter expressions accordingly. [1] [2]

User Interface and Settings:

• Added a new checkbox input in the settings UI to enable or disable the expression filtering feature. [1] [2]
• Updated the slash command parser to include a new filter argument for the expression-list command, allowing users to filter expressions via slash commands. [1] [2] [3]

[cloak1505]

On/off works as expected. This position of the checkbox is definitely better than I had initially thought up of.

When I try /expression-list filter=true | /echo {{pipe}}, filter=true and false both return the full unfiltered list. Is something wrong?

The help for /expression-classify shows [filter=true|false]? = true, does this mean the default is true? But it acts like the default is false but does filter when I explicitly type in /expression-classify filter=true foobar.

[Wolfsblvt]

When I try /expression-list filter=true | /echo {{pipe}}, filter=true and false both return the full unfiltered list. Is something wrong?

The actual argument being read was different than the documentation said, still had it on filterAvailable, but later shortened it in the doc. Fixed that. Thanks for catching that.

The help for /expression-classify shows [filter=true|false]? = true, does this mean the default is true? But it acts like the default is false but does filter when I explicitly type in /expression-classify filter=true foobar.

Same here, oversight. And yes, the default is planned to be true for the slash command. I think it makes sense to set it to true. Though I am open for opinions. Not sure if the general setting/toggle should also bei initialized to true.