[IMP] {purchase_, sale_}stock{_account}: improve forecast report UX

Minor UX updates to forecast report:

- add missing space (between # and unit + before |) also removed
  superfluous uoms (only need it at the end now that an equation is
  displayed)
- move On Hand Value to under product link (+ variants if they exist)
  and make it a link to the valuation report of the product(s) in
  question
- add link from Quantity on Hand to the locations (i.e. inventory/quants)
  report for the relevant product(s). Note that product template was
  added to Search in order to support default searching due to
  forecasting report structure
- redo the top right forecast values to be On Hand + Incoming - Outgoing
  = Forecasted so we provide more explicit and transparent values.
  Additionally, these values are made to not display decimal digits if
  all of those digits are 0.  Note that forecasted values in table are
  untouched (i.e. Forecasted Inventory = Forecasted is unchanged and
  Forecasted with Pending still shows in table)

Also did some t-esc => t-out replacement and other small cleanup since
templates were already being edited.

"forecasted report" part of b2b task: 2882539

Part-of: odoo/odoo#97109