Remove remaining legacy backbone form input elements

[guerler]

This PR removes the final two backbone-based form input elements, namely ftpfile and library_data.

ftpfile has only been used internally by the upload tool which uses a different UI and does not rely on the regular form components, hence the legacy backbone wrapper can simply be removed.

After some discussion, and initially replacing the library_data input, we decided to remove this input since it's functionality is fully covered by the regular data input and it is not used on any of the public instances in addition to being unavailable in the toolshed. Thanks @mvdbeek for verifying that.

Moving forward, neither of these two inputs should be used. Instead tool developers who would like to use ftp or library datasets as inputs should use the regular data input field. This field already allows users to select these types of datasets through the data dialog.

Additionally, this PR follows up by removing additional unused backbone legacy files.

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[mvdbeek]

Thanks @mvdbeek for verifying that.

There is a single tool on the tool shed actually, https://toolshed.g2.bx.psu.edu/view/damion/blast_reporting/812de0e282bd ... but it has the library_parm parameter commented:

                <!-- Disabled until Galaxy bug fixed for this.
                <param name="library_datasets" type="library_data" label="Reference Bin file" help="Select one reference bin at a time from the popup window's Reference Bin library."/>
                -->

so i'm pretty sure we're not breaking anything. I'm just gonna push a commit removing this from the schema.

[mvdbeek]

Thank you!

[guerler]

@mvdbeek, thank you for your review and help!