…e buffer

When a overlay is displayed at the end of the buffer, (window-end) may return
a value that is past the end of the buffer. Calling line-number-at-pos with a
value outside of the buffer bounds raises an error.

Only the parser

…tion

…displayed

Check if company is active before displaying the overlay -- hide it if so

Add a list of predicates that can inhibit triggering inline completions --
e.g.:

    ```elisp
    (defun lsp-inline-completion-inhibit-if-company-active ()
        (and (bound-and-true-p company-mode) (company--active-p)))

      (push 'lsp-inline-completion-inhibit-if-company-active lsp-inline-completion-inhibit-predicates)
    ```

…Context

Also, refactor how we parse the response, using pcase for a more explicit approach

Users can enable the lsp-inline-completion-company-integration-mode if they
see fit.

Other completion frontends may be customized via hooks, just as this minor
mode does

…ginal buffer

lsp-inline-completion--after-change, added to lsp on-change hooks, is
triggered on a timer by `lsp--after-change`. The inline completion
maybe-display function is also triggered on a timer and it must check if the
position and current buffer did not change since the change as actually
occurred.

We can not store this state in lsp-inline-completion--after-change because the
user may have clicked somewhere before the timer activated it.

This commit introduces a `lsp--after-change-vals` plist to store the context
before the timers have been started.

lsp-inline-completion--after-change then fetches these values and forward as
arguments to the timer invocation of maybe-display, which then ensures that
the state has not changed.

It is a distraction.

Auto-substitution of tabs to space did not use the correct number of spaces