Rename searchsorted* functions to findsorted*

[nalimilan]

The name is consistent with the new API, as search no longer exists.
Also swap the two positional arguments for consistency with other functions.

Alternative approach to fix #24883. Replaces #25133, part of #10593.

[JeffBezanson]

One reason I prefer the old names is that they implement "binary search", which is a commonly-recognized term.

[nalimilan]

Then they should be called binarysearch, not searchsorted. There's also the annoyance that the arguments are in reverse order compared with other functions.

[mschauer]

findsorted suggests the function looks for a sorted (sub-)sequence, if the name is an analogy to findmax (finding the maximum), findlast (finding the last occurence) etc.

[nalimilan]

For triage: the question of the name is somewhat secondary, what concerns me more is the fact that the order of arguments of the searchsorted* functions is currently the opposite of the find* functions. So there are two decisions to make:

• should we change the order of arguments for consistency
• should we use the occasion to rename the functions too

[StefanKarpinski]

My feeling is that we should just leave these alone. If we ever come up with a better coherent API using find functions and SortedVector types, that would be great, but at that point, we can just introduce that and have these as a legacy API until 2.0 comes around. (This seems to be the general sentiment from triage as well.)