[Feedback] Rule action templating

Rule action templating allows rules to dynamically set fields based on transaction data.

To enable the feature - head over to experimental features and toggle the rule action templating feature flag. Next, go to the "rules" page and set up a new rule.

To use it, click the icon on the right hand side of the input box to toggle from "text" to "template" mode:
Text mode:
Template mode:

Then enter your template. For example, the below will replace the notes field with the VAT paid (standard VAT is 20% in the uk)

At the moment, templating is supported for setting:
- notes
- date
- amount
- cleared (although no boolean helper functions are currently supported)

Full list of available helper functions:
- `regex value regex replacement`
- `add num1 num2 ...`
- `sub num1 num2 ...`
- `div num1 num2 ...`
- `mul num1 num2 ...`
- `mod num1 num2 ...`
- `floor num`
- `ceil num`
- `round num`
- `abs num`
- `min num1 num2 ...`
- `max num1 num2 ...`
- `fixed num1 num2`
- `day date`
- `month date`
- `year date`
- `format date format`
- `debug value` (logs to console)
- `replace value pattern replacement` mimics js replace. When pattern is not as `/regex/flags` it just uses raw value as opposed to `{{regex ...`
- `replaceAll value pattern replacement` mimics js replaceAll
- `addDays date days` add x days to the day
- `subDays date days`
- `addWeeks date weeks`
- `subWeeks date weeks`
- `addMonths date months`
- `subMonths date months`
- `addYears date years`
- `subYears date years`
- `setDay date day` Overflows are handled, 0 will set to last day of month before
- `concat args..` joins all arguments together

Full list of available variables that can be used
- `today (date)`
- `account (id)`
- `amount (number)`
- remember this is stored _without_ the decimal place. ie. £152 will be `15200`. `{{div amount 100}}` can be used to convert back
- `cleared (boolean)`
- `date (date)`
- `error (?)`
- `imported_id (id)`
- `imported_payee (string)`
- `is_child (boolean)`
- `is_parent (boolean)`
- `notes (string)`
- `parent_id (id)`
- `payee (id)`
- `reconciled (boolean)`
- `schedule (id)`
- `sort_order (number)`
- `starting_balance_flag (boolean)`
- `tombstone (boolean)`
- `transfer_id (id)`
---
Feel free to share your ideas, bug reports and feedback below.