- Added Custom Field for Print Designer Template Location
- Added Hook to define folder location for Print Designer Templates
( location fallbacks to default_templates if not defined in hooks for export )

- when print designer is installed, loop over all apps and import standard templates.
- when any new app is installed, check if it has print designer templates and install them.
    - it also checks print_designer app for new templates and installs them.

- Modified export functionality for print formats that are made using print_designer.
    - it will export print format in custom directory if defined in hooks else in default_templates folder.
    - user / developer can define app where print format should be exported in print_designer_template_app field.

added new custom field "print_designer_preview_img" to store the format preview image.
added html2canvas
on save
- make copy of main-container dom and convert to canvas using html2canvas.
- create file instance and pass blob to it from canvas.toBlob()
- send file to /api/method/upload_file , client side function is just modified version of FileUploader.
- remove old format preview image after new one is uploaded successfully.

This will be used to display the format preview in the format Grid View.

dynamic text value is fetched from db so there is no need to save it as part of format.

we have to consider and load metaFields from db so remove it from Print Format JSON.

- if standard is set to true, remove static file urls as it can't be used across site.
- only try to load file if url value exists for the file.
    - This doesn't check if image file exists or not.

As standard field returns Yes or No, update the logic to compare string instead of boolean.

update preview image url in print_designer_preview_img field

First check if table exists before trying to load childfield meta

Copy the image to the export directory so that it can be used for preview while installing the format.

when print_designer format is saved in developer mode and format is standard.
preview images and " File " document is exported as per the location defined in the selected app's hook.
after install once the formats are imported, copy the file to private/files folder and update the file path in the format.

After merging relative containers when this in this PR conflicts were manually resolved.
There were some incorrect conflict resolutions, which are fixed in this commit.

Also, removed multiple updates for print format document caused by updating file_url.
instead get latest file_url from the file document else set to null.

while refactoring the code, by mistake it was changed to an array. This commit fixes it.

unintended cssRules were removed by mistake so until that can be fixed removing deleteRule code.

image upload sometime happen before the format is saved and sometimes after.
handled both cases based on isFormatSaving flag.

revert this after frappe/frappe#25779 is released in v15

when we create copy when user updates the formats with old schema.
it was implicitly setting the name with copy + number suffix.
now we set that name as default and prompt user if they want to change the name.