Refactor `with_defaults()`

[AshesITR]

lintr/R/zzz.R

Line 65 in b4747a3

if (inherits(x, "function") && !inherits(x, "lintr_function")) {

let's use is.function(x) instead?

f = lm
class(f) = 'boo'
inherits(f, 'function')
# [1] FALSE
is.function(f)
# [1] TRUE

Originally posted by @MichaelChirico in #1015 (comment)

[AshesITR]

Thoughts on this:

• The new preferred way of configuring lintr should be linters_with_tags(), which, without arguments, yields results equivalent to with_defaults() without a default = argument, as is used in .lintr files. (tags= argument for available_linters() #980)
• with_defaults() must not break immediately, but should be deprecated in favor of linters_with_tags()
• A better name for what with_defaults() does is modify_defaults().

[AshesITR]

In view of the fact that we might add google_linters as a pre-configured object, we'll still need something like with_defaults(), so I will deprecate-rename to linters_with_defaults(..., default = default_linters) instead