Fix a bug related to custom catalog objects in the Observation Planner, and add a convenient "Batch add" feature to the Observation Planner.

This MR makes two changes that impact the Observation Planner:

• It fixes a bug related to custom catalog objects. (Previously part of !87 (closed) -- cherry picked and transferred here) You could previously add objects from custom catalogs to the Observing Wishlist, but when you reloaded the Wishlist from file by restarting KStars, they would not be found. This is because CatalogComponent::findByName was not implemented. The MR fixes the bug by implementing CatalogComponent::findByName(). This may need to be adapted to work with !93 (merged) but @vboettcher has green-lighted this change.

• It adds a "Batch add" button to the observing list. This button allows the user to copy-paste a list of objects, one object on each line, and add it to the wish-list or session plan (whichever tab is active). The refactoring of FindDialog needed by this change might conflict with @vboettcher's DSO overhaul !93 (merged). However, I believe it should not cause a lot of conflict, and it is better to merge this as this is mostly a separate feature. The Batch Add feature will be useful for users who want to paste their observation lists in CSV and other formats into KStars -- they just need to open a CSV list in Excel, copy the column with the object IDs, and paste it into KStars.

In addition, there are some minor improvements, such as trying to match the wishlist entries with the names in the skycomponents a bit better (ignoring multiple spaces etc.)