This PR removes the vInt that precedes every value in order to know how long
they are. Instead the query takes an enum that tells how to compute the length
of values: for fixed-length data (ip addresses, double, float) the length is a
constant while longs and integers use a variable-length representation that
allows the length to be computed from the encoded values.

Also the encoding of ints/longs was made a bit more efficient in order not to
waste 3 bits in the header. As a consequence, values between -8 and 7 can now
be encoded on 1 byte and values between -2048 and 2047 can now be encoded on 2
bytes or less.

Closes #26443

This PR removes the vInt that precedes every value in order to know how long
they are. Instead the query takes an enum that tells how to compute the length
of values: for fixed-length data (ip addresses, double, float) the length is a
constant while longs and integers use a variable-length representation that
allows the length to be computed from the encoded values.

Also the encoding of ints/longs was made a bit more efficient in order not to
waste 3 bits in the header. As a consequence, values between -8 and 7 can now
be encoded on 1 byte and values between -2048 and 2047 can now be encoded on 2
bytes or less.

Closes #26443

* master: (39 commits)
  [Docs] Correct typo in removal_of_types.asciidoc (elastic#26646)
  [Docs] "The the" is a great band, but ... (elastic#26644)
  Move all repository-azure classes under one single package (elastic#26624)
  [Docs] Update link in removal_of_types.asciidoc (elastic#26614)
  Fix percolator highlight sub fetch phase to not highlight query twice (elastic#26622)
  Refactor bootstrap check results and error messages
  Add BootstrapContext to expose settings and recovered state to bootstrap checks (elastic#26628)
  [Tests] Removing skipping tests in search rest tests
  Initialize checkpoint tracker with allocation ID
  Move non-core mappers to a module. (elastic#26549)
  [Docs] Clarify size parameter in Completion Suggester doc (elastic#26617)
  Add soft limit on allowed number of script fields in request (elastic#26598)
  Remove MapperService#dynamic. (elastic#26603)
  Fix incomplete sentences in parent-join docs (elastic#26623)
  More efficient encoding of range fields. (elastic#26470)
  Ensure module is bundled before installing in tests
  Add boolean similarity to built in similarity types (elastic#26613)
  [Tests] Remove skip tests in search/30_limits.yml
  Let search phases override max concurrent requests
  Add a soft limit for the number of requested doc-value fields (elastic#26574)
  ...