Current value added to asset index page

[akemidx]

Current value has been added as a column in the assets index page.

FIxes: FD-36095

Additionally, translations have been added in the Warranty and Depreciation column headers when exporting reports.

Cocurrently, I discovered that Current Value is not sorting correctly, tho looking like it should. This is occuring in multiple places, and is a fix that is out of scope for this PR. Therefore, CV will NOT correctly sort high to low or low to high at this time.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

tested locally

Checklist:

• I have read the Contributing documentation available here: https://snipe-it.readme.io/docs/contributing-overview
• I have formatted this PR according to the project guidelines: https://snipe-it.readme.io/docs/contributing-overview#pull-request-guidelines
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[what-the-diff]

PR Summary

• Modified conditions for adding headers in ReportsController.php
  The conditions for adding headers in the "ReportsController" were updated, removing "Warranty" and "Depreciation" headers, and adding new headers for "book_value" and "warranty".

• Added key-value pair to AssetsTransformer.php output
  A new key-value pair was added to the transformation output in "AssetsTransformer", with the "book_value" key storing the linear depreciated value of the asset.

• New column definition added to AssetPresenter.php
  A new column definition was added to the "dataTableLayout()" method in "AssetPresenter", with the field name "book_value" and the title "book_value".

[snipe]

Looks great, ty! We’re going to need to address the search/sort thing down the line, but this is a great start!