Various fixes and improvements to the Demo

[donhardman]

• [x] improve exceptions handling, especially the exception which is thrown when the token has exceeded its limit
• [x] experiment more with the facets UI to make it less confusing (grey out filters that would result in zero results etc.)
• [x] deploy a new version of the embedding generations from php-ext-model
• [x] add a script that will recalculate float vectors without altering data

[donhardman]

During this task, we improved exception handling: https://github.com/manticoresoftware/manticore-github-issue-search/issues/8

[donhardman]

Vector search fixes was implemented and merged in this pull: https://github.com/manticoresoftware/manticore-github-issue-search/pull/13

[donhardman]

The latest UI improvements were implemented in this pull request: https://github.com/manticoresoftware/manticore-github-issue-search/pull/18

[donhardman]

Closing due it's merged and deployed