Add a new constructor for all Krylov solvers

[amontoison]

close #948

Needed for CliMA/Oceananigans.jl#4041.
A more generic constructor for our KrylovSolvers is required to support custom vector types.
I was aware of this limitation, but addressing it requires significant work, as a new workspace constructor must be implemented manually for each Krylov solver.

To resolve the issue, I created a new constructor that takes a single argument (a KrylovConstructor or a BlockKrylovConstructor).
The KrylovConstructor encapsulates (custom) vectors on which we can apply similar to create the necessary workspace.

Since some Krylov solvers, such as least-squares and least-norm solvers, require vectors of varying lengths that cannot be determined / created solely from the right-hand side vector b, only the in-place version of the Krylov method can be used in such cases.
The corresponding KrylovSolver is created with a KrylovConstructor.

cc @michel2323

[codecov]

Codecov Report

Attention: Patch coverage is 99.24528% with 6 lines in your changes missing coverage. Please review.

Project coverage is 93.19%. Comparing base (9536ef7) to head (9baae40).
Report is 30 commits behind head on main.

Files with missing lines	Patch %	Lines
src/block_gmres.jl	0.00%	3 Missing ⚠️
src/block_krylov_solvers.jl	0.00%	2 Missing ⚠️
src/krylov_utils.jl	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #947      +/-   ##
==========================================
- Coverage   94.68%   93.19%   -1.49%     
==========================================
  Files          45       46       +1     
  Lines        8027     9181    +1154     
==========================================
+ Hits         7600     8556     +956     
- Misses        427      625     +198     

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