What are the combinations of the consonants ch, sh, th, wh, ph called in the professional literature jargon? (I'm asking about the consonants that are represented by two letters).
They are called consonant digraphs.
Consonant blends (also called consonant clusters) are groups of two or three consonants in words that makes a distinct consonant sound, such as "bl" or "spl."
Consonant digraphs include bl, br, ch, ck, cl, cr, dr, fl, fr, gh, gl, gr, ng, ph, pl, pr, qu, sc, sh, sk, sl, sm, sn, sp, st, sw, th, tr, tw, wh, wr. Some trigraphs are nth, sch, scr, shr, spl, spr, squ, str, thr.
There are also digraphs that produce a distinct vowel sound. Some examples are: ai, au, aw, ay, ea, ee, ei, eu, ew, ey, ie, oi, oo, ou, ow, oy. (source)